Characterisation, Measurement & Analysis
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Applications

  • Rigol’s New Real-time Spectrum Analyser

    Never Miss a Signal

    Today’s RF designs utilise rapidly changing and pulsing signals that are difficult to consistently capture on traditional swept spectrum analysers. The Rigol RSA5000 delivers a class leading 7.45µsec 100% probability of intercept meaning that any pulse with a duration of greater than 7.45µsec will be captured and accurately displayed.

    Isolate & Capture

    IoT Device proliferation means more traffic crowding the available spectrum making identifying and isolating signals of interest critically important. The Rigol RSA5000 includes advanced trigger capabilities making this task easier.

    Frequency Mask Trigger captures and displays data when the signal crosses inside or outside of the masked region allowing the engineer to focus on critical signals and ignore interfering ones.

    Power Trigger allows the engineer to trigger and display only when a power level is exceeded within the real-time span.

    Trigger Input & Output allow the engineer to time correlate RF events with other system elements to quickly find root cause of system problems.

    IF Output recreates the real-time bandwidth on a 430MHz carrier for further analysis.

    Visualize & Analyse

    Complex modulating and pulsing signals require advanced visualisation tools to identify patterns and debug designs. The Rigol RSA5000 provides 7 Realtime Visualization modes to look at signal behaviour versus power, frequency and time. 6 markers, 4 trace types, and trace math capabilities allow engineers to quickly analyse and understand signal behaviour across the entire span.

    7 Display Views

    Normal Display Similar view to traditional analysers. Traces, Cursors for traditional measurement. Simple Data view for initial investigation.

    Density Display Colour map represents signal probability at each frequency and power level. See time varying signals with the Real-time span. Separate superimposed “hidden” signals. Resolution of signals on same frequency band.

    Spectrogram Display Observe signal changes over time. Analyse frequency hopping patterns. Characterise PLL Lock and Settle time. Identify sources of interference.

    Density and Spectrogram Display Combine the insights of the Density Display with changes over time. See pulsing signals inside crowded spectrum. Separate WiFi from Bluetooth and other traffic.

    Power v Time (PvT) Display Display the RF Power for the Real-time span over a defined time period. Evaluate the duration of pulsing signals. Investigate ASK and other amplitude modulations by monitoring power level changes. Determine the timing of pulsing signals.

    PvT and Spectrum Display Display the RF Power for the Real-time span over a defined time period along with the frequency. View not only the RF power, but time correlate the Frequency Data.

    PvT and Spectrogram Display the RF Power for the Real-time span over a defined time period along with the frequency and time. View not only the RF power, but time correlate the Frequency Data. Observe the frequency and power change over time.

    RSA5000 Real-time Spectrum Analysers

    High performance Swept Spectrum Analyser

    • 2GHz and 6.5GHz Models with available TG
    • 1ms Full Span Sweep
    • 1Hz RBW
    • Low Noise Floor as low as -165dBm

    Superior Real-time Performance

    • Up to 40MHz Real-time Bandwidth
    • 45µsec 100% POI
    • 7 Visualization Modes
    • Advanced Triggering

    Flexible User Interface

    • 1” Capacitive Touch Screen Display
    • USB Keyboard/Mouse
    • Knob and Softkey Controls
    • HDMI Out
    • USB/LAN support

    Features and Benefits

     

    Product Feature Customer Benefit
    DANL as low as -165 dBm with       optional preamp View lower powered signals (harmonics, interference sources) and ease trouble-shooting in swept and real-time mode.
    1 Hz Minimum Resolution Bandwidth (RBW) Provides high resolution to separate signals with close frequencies enabling easier signal identification for characterisation and advanced measurements.
    1 ms full span sweep Utilise the fast 1 millisecond full span sweep to quickly identify signals of interest.
    Up to 40 MHz of Real-Time BW View wider band and hopping signals at one time without additional setup making identifying and analysing signals of interest faster and easier.
    7.45 µs 100% POI Capture pulsed transmissions as short as 7.45 µs with guaranteed capture and power accuracy.
    7 Real-Time Visualization Modes Advanced debugging and analysis with combinations of Normal, Density, Spectrogram, and Power vs Time visualizations.
    Powerful triggering capabilities Identify specific signals of interest with frequency mask, power triggers, or use external triggers to time correlate digital signals for additional analysis.
    Tracking Generator and VSWR measurements Use the optional tracking generator to test cables, antennas, filters, and active components. VSWR automates standing wave parameter measurements.
    Flexible usability options Use front panel buttons, touch screen, keyboard/mouse/monitor, and PC based software control in any combination to match the application and customer preference.
    EMI filters and detectors Standard 6 dB filters for EMI bandwidths as well as Quasi Peak detectors.

     

    If you would like more information, arrange a demonstration or receive a quote for the Rigol RSA5000 Series; you can contact us via email, through our website or call us on 01582 764334.

    We also supply and service an extensive range of test & measurement products from our list of industry leading manufacturers. Click a manufacturer logo below to see their range of products on our website.

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

  • Ultra High Resolution OSA: a perfect tool for optical Orthogonal Frequency Division Multiplexing (OFDM) measurement and adjustment

    The Ultra High Resolution OSA (UHR-OSA) proposed by APEX Technologies remains a very important tool not only to measure the optical OFDM (Orthogonal Frequency Division Multiplexing) signal spectrums even with few tens of MHz spacing sub-carriers but also to adjust and adapt it to other modulation techniques.

    APEX-UHR-OSA incessant need in OFDM research area

    APEX UHR-OSAs have found a wide industrial and academic success marked by the incessant demand of researchers and experts in all aspects of the OFDM technique. Indeed, more than 30 APEX-UHR-OSAs are currently used throughout the world by several universities such as Dublin City university (IRELAND) [1], Melbourne university (AUSTRALIA), IT AVEIRO (PORTUGAL), Bangor university[2],… and industries such as Orange Labs [3], KDDI R&D Lab [4],…

    What is OFDM?

    Optical OFDM (Orthogonal frequency division multiplexing) is a promising format for the next generation of long-haul and access networks because of its high spectral efficiency and the resistance to a variety of dispersions including chromatic dispersion (CD). The basic principle of OFDM technique is to carry information using several hundred sub-carriers which transport a fraction of the data rate each. The main feature of OFDM resides in the orthogonality of its sub-carriers obtained by spacing each of them with a multiple of the inverse of symbol duration (of the low bit-rate streams).

    Its main advantage is to avoid the inter-carrier interference and to allow spectral overlapping in order to ensure a high spectral efficiency. The orthogonality is maintained by adding a cyclic prefix to each OFDM symbol in order to eliminate the inter-symbol interference (ISI). In terms of transmission, OFDM has received increased attention thanks to its robustness to ISI, namely chromatic dispersion (CD) and polarisation mode dispersion (PMD), provided by the low sub-carrier data rate without any need for complex equalisation at the receiver side. For this reason, increasing the sub-carrier number is very crucial so that each sub-carrier transports the lowest possible bit-rate stream (equal to the nominal bit-rate divided by the number of sub-carriers). In frequency domain, it corresponds to a few ten of MHz (typical 20 MHz to 50 MHz) sub-carrier spacing. Fibre-optic OFDM systems can be realised either with direct detection optical (DDO) or with coherent optical detection (COD).

    What else makes APEX-UHR-OSA so good?

    Figure 1: Double Side Band (DSB) OFDM spectrum measured by APEX-UHR-OSA taken from [5]

    The key feature of the APEX-UHR-OSA is its capacity to measure the OFDM signal spectrum and to display all the sub-carriers clearly even with a few tens of MHz spacing, this is not possible with a traditional grating based OSA resolution (down to 20 pm/ 2.5 GHz). Based on an interferometric method, APEX Technologies UHR-OSA combines high resolution (up to 5 MHz, 0.04 pm), wavelength accuracy (+/- 3 pm) and high dynamic range. These equipment specifications (in particular the resolution) are good enough to see the details and the separation between adjacent sub-carriers (figure 1).

    Click here for more information

  • Ultra High Resolution OSA for Characterising and interrogating Fibre Bragg Grating Sensors

    The APEX Technologies Ultra High Resolution Optical Spectrum Analyser (OSA) can be used to measure the active/passive optical component insertion loss/gain thanks to the possibility to synchronise the internal Tunable Laser Source and the OSA sweepings. In this context, the APEX OSA remains a perfect tool to measure the Fibre Bragg Grating (FBG) Sensor reflection with 1 MHz of resolution, 63 dB dynamic and 0.3 pm wavelength relative accuracy.

    Introduction to Fiber Optic Sensors

    Optical fibres technology was first realised in the 1960s and has developed to be an integral part of modern telecommunications. Over the last few years, fibre optics and optoelectronics industry have seen tremendous amount of innovation and widespread use leading significantly reduced optical component cost with an improved quality. By taking advantage of these economies of scale, fibre-optic sensors were designed to measure the performance and status of optical networks. In addition to telecommunications applications, optical fibre sensors have moved from experimental research applications in the lab to broad usage and applicability in field applications such as oil and gas services, medical and biomedical engineering, electrical power industry, structural monitoring, defence and aerospace.

    Click here for more information.

  • The Phenom XL is tested as the best tabletop SEM

    Early this year, an anonymous experienced SEM researcher evaluated different tabletop SEM systems. Frustrated by the lack of honest (read impartial) reviews of the tabletop SEM systems, he has made a website to help others find the system that is right for them based on his findings and experience.

    It is great to see that the Phenom XL has a 5-star review as the best top-performing tabletop system compared to the Hitachi TM3030, JEOL NeoScope and SEC SNE-4500.

    Click here to see the complete comparison table of specifications for the four best tabletop scanning electron microscopes currently on the market.

    Lambda Photometrics are the UK and Ireland distributors for sales, service and applications and have been working with Phenom-World for many years. Click here for more information alternatively please contact our Sales Engineers on 01582 764334 or at contact@lambdaphoto.co.uk.

  • Why buying Stanford Research Systems from Lambda makes sense

    For 30+ years Lambda Photometrics have represented Stanford Research Systems (SRS) in the UK as SRS’s authorised UK distributor and service centre with unparalleled experience of supporting their products.

    To ensure best value for money some companies require several quotes to satisfy their organisation’s purchasing policy. In order to clarify any confusion over comparisons between Lambda’s pricing and SRS’s International list price, we would like to highlight a few points in the table below to show why it makes sense to purchase direct from Lambda Photometrics.

     

    Our prices should always be fair and compatible with SRS direct when you factor in freight, additional import duty charges, customs documentation, immediate local support and other hidden extras that people often miss. As the longstanding UK representative for SRS, our experience, pre and post-sales support can’t be matched.

    If you would like to discuss or compare a quote please feel free to contact us - 01582 764334 or email.

  • Absolute Position Measurement: Multiwavelength-interferometry-based sensor redefines precision position metrology

    An absolute position measurement system has a noise floor of less than 0.02 nm/√Hz over a range of 1.2 mm.

    Measuring to the nanometer scale is no small feat—getting there takes careful engineering and a fundamentally good sensor. The sensors used for stage position feedback inside semiconductor lithography tools regularly achieve this level of precision. Zygo has supplied displacement measuring interferometers (DMIs) to satisfy this application for 30 years.

    Zygo has recently introduced the ZPS, an optical sensor system that delivers absolute position with subnanometer precision. Many sensors in the market claim to have this capacity—without an industry-standard definition, though, it is difficult to compare two different sensors and know what performance to expect. This article shares our experience, clarifies the common terms that describe the quality of a position sensor, and shows how ZPS delivers good performance.1

    The ZPS system is a fiber-based optical sensor system that provides absolute position with low noise (≤0.02 nm/√Hz) and high repeatability (0.5 nm 3σ) over a 1.2 mm travel range. The system supports up to 64 synchronised channels with user-selectable data rates up to 208 kHz. It has utility in applications that require a high quality of measurement, a large number (>16) of measurement channels, or both.

    Optical sensors provide several advantages over other technologies like capacitance gauges or encoders. Optical sensors are capable of direct measurements, insensitive to electromagnetic interference, and generate no heat. Cabling restrictions are minimal, as fiber cables can be quite long and are more flexible than electrical cables. ZPS sensors are very compact (3 × 27 mm on average) and enable metrology in applications with severe space constraints.

    How ZPS works

    ZPS combines three kinds of interferometry in a single device: multiwavelength, heterodyne, and coupled-cavity interferometry (see Fig. 1).

     

    FIGURE 1. The chassis (a) and sensor (b) are shown for a ZPS absolute-position sensor; the sensor is based on multiwavelength (c), heterodyne, and coupled-cavity interferometry (d).

    Multiwavelength interferometry is the technique of reconstructing absolute distance between two surfaces by solving multiple instances of the equation:

    2d = mλ + φ

    where d is the distance between the sensor reference surface and the target, λ is wavelength, and φ is the fractional (residual) interference term. The process for solving these equations is called the Method of Exact Fractions and was developed by Jean-René Benoît in 1898.

    Multiwavelength interferometry enables ZPS to measure the actual distance between the sensor and the target. ZPS performs this technique by using three known wavelengths, measuring the residual interference terms and then solving for m and d. ZPS's algorithms result in a ≤0.5 nm 3σ repeatability. The process is done on all channels simultaneously in a one-second calibration step-heterodyne displacement interferometry is then used to track changes in d thereafter.

    Heterodyne interferometry uses two frequencies of light to generate a constant signal because of temporal interference. This concept is analogous to FM radio, which modulates a carrier frequency to transmit information, resulting in a lower noise floor and better performance. This is why music sounds better on FM radio—the same improvement holds true for position interferometry. ZPS uses an electro-optic modulator to generate the carrier frequency.

    Coupled-cavity interferometers are used in conjunction with low-coherence light sources to measure displacement over short distances. A reference cavity establishes the nominal zero point of the measurement arm of the interferometer. ZPS employs this architecture by introducing a delay between the modulated and unmodulated light. This path delay sets the nominal standoff between the sensor and the target. A thermally stabilized cavity inside the system tracks for variations in the path delay and compensates the data in real time.

    The table shows key performance specifications for ZPS—some of these terms are commonly published by all sensor manufacturers. The resolution is naturally taken to be the indicator of a performance and the metric by which different options are compared. However, with no standard in place, this number means different things when said by different companies. As always, the devil is in the details and it is important to read the fine print to understand what any of these specifications are saying about the performance of the sensor.

    Resolution: what does it really mean?

    Resolution may be the most misunderstood term used to describe a sensor's performance. In some cases, it is just the smallest counting increment from the device—the noise floor may be orders of magnitude higher. In other cases, it includes noise, but either fails to specify the bandwidth or hides it in very fine print. Low bandwidths and rolling averages trade dynamic response for improved resolution. It is always prudent to ask the supplier the bandwidth at which the resolution is specified.

    Zygo uses the term digital resolution to indicate the smallest counting increment available. It is important that this number be below the noise floor (but not too far) to resolve the noise-limited performance of the sensor. With ZPS, we specify the digital resolution (0.01 nm), a bandwidth-independent noise (0.02 nm/√Hz), and the maximum bandwidth (104 kHz). These specifications can all be achieved simultaneously.

    In addition to resolution, some companies are less than direct with other sources of error in their sensors. Zygo understands the total measurement uncertainty of our products and shares this with our customers.

    FIGURE 2. Graphs of performance data from the ZPS sensor show long-term stability (a); nonlinear error, full-stroke range (b); noise, full-stroke range (c); and system repeatability (d).

    Uncertainty: the real performance metric

    The total uncertainty of a sensor system is the truest measure of its performance. Understanding uncertainty can be a graduate-level college course unto itself. The essential aim is to combine all the possible error sources statistically to generate a standard deviation. ISO's Guide to the Expression of Uncertainty in Measurement (also known as the GUM) provides a thorough overview of the process.2 In addition to noise, major sources of uncertainty for position sensors include environmental effects, nonlinearity, stability of length scale, and mounting.

    Bob Hocken, former director of the Center for Nanoprecision Metrology and Distinguished Professor at the University of North Carolina Charlotte, once quipped, "Every machine I ever made was also a thermometer." It is no surprise that temperature changes affect sensor behavior. Noncontact sensors must also consider pressure, humidity, and gas content when operating outside of a vacuum. ZPS has a refractometer accessory that detects the actual refractive index of the air, and automatically compensates sensor measurement values against environmental effects in real time to subnanometer levels.

    Each sensor technology has its own sources of nonlinearity. For interferometers, this typically comes from spurious reflections and manifests itself as a sinusoidal error in the data, earning it the name cyclic error. For other sensor technologies, nonlinearity may come from the limits of the factory calibration. It is important to know that these terms exist and how big they are. ZPS deals with nonlinearity by factory calibration for low-order terms and through a patented active compensation process for cyclic error. The result is a very low residual nonlinearity of ±1 nm.

    The stability of a sensor's length scale is a fundamental consideration for achieving low uncertainty. The length scale for interferometer systems is the wavelength of light used in the measurement. ZPS actively monitors changes in wavelength using thermally controlled cavities housed within the chassis. The system continuously applies compensation for wavelength changes to the measured data automatically. ZPS's specification is ≤1 nm/day, although qualification data shows actual stability to be significantly better.

    Sensor mounting is a consideration often overlooked by designers new to the challenges of precision metrology. Motion of the sensor mount is indistinguishable from motion of the target, regardless of the technology used. It is crucial to identify the sensor's reference surface and keep it fixed over the anticipated thermal and vibration ranges. ZPS's reference surface is on the front face of the sensor, allowing for the design of a tight metrology loop. Other sensors have ill-defined reference surfaces or bury them within the sensor package, adding uncertainty and making it more difficult to produce good metrology.

    ZPS performance

    Despite all the challenges, nanometer-level metrology is possible. The graphs in Fig. 2 show example data of actual ZPS performance. Descriptions of the test conditions are provided below.

    Stability. Zygo evaluates stability by measuring air-spaced Zerodur cavities in a standard lab environment (±0.5°C), with environmental compensation applied via refractometer accessory. To isolate the stability measurement from noise, each data point represents an average over one second. The result is <0.2 nm drift over a four-day period.

    Nonlinearity. ZPS data is taken simultaneously against a helium neon laser-based DMI system. The graph shows the bounds of the cyclic error superimposed on the low-order effects. Low-order nonlinearity comes from the phase change as the target travels through the beam focus. The result is a ≤±0.4 nm nonlinearity over the full measurement range.

    Noise. Zygo uses solid-glass etalons to eliminate mechanical vibrations. The measurements were taken in a nominal lab environment at 5 kHz and then converted into a bandwidth-independent noise figure. ZPS has a tiered specification where the central ±100 μm range has a fourfold improvement in noise compared to the full range.

    Repeatability. Air-spaced Zerodur etalons are used to eliminate mechanical noise. The calibration routine that establishes absolute distance is run repeatedly over the course of several hours. The result is shown to be well below the 0.5 nm 3σ specification for seven different test etalons.

    With a clear understanding of uncertainty, it is easier to compare sensors, even when they employ disparate fundamental technologies. Zygo's precision metrology experience enables production of position sensors like ZPS to meet the uncertainty needs of a wide range of applications.

    REFERENCES

    1. See U.S. patents 7,636,166; 7,639,367; 7,826,064; and 9,115,975.

    2. See www.bipm.org/en/publications/guides.

    About the author: Ernesto Abruña is the product manager for precision position sensors at Zygo Corporation. Originally published in www.LaserFocusWorld.com on 10th July 2017

  • Imaging fibres with a SEM: how to obtain a flawless quality analysis

    In our daily life, we make use of a large amount of objects and devices that are produced from fibres. Fibres are usually imaged in a scanning electron microscope (SEM), which provides high-resolution images, elemental analysis, and the possibility of automatically measuring thousands of fibres in mere minutes. But in some cases, imaging fibres with a SEM also presents challenges, as the nature of some fibres might compromise the quality of your analysis. With this in mind, this blog describes how you can obtain a high analysis quality through proper SEM configuration and sample preparation.

    We can distinguish two different kinds of fibres, natural and man-made. Natural fibres can be classified in vegetable fibres, that are for instance based on cellulose and used in the manufacturing of paper or cloth, animal fibres, such as wool, mineral fibres , like asbestos, and biological fibres, including muscle proteins, spider silk and also hair. Man-made fibres range from the synthetic fibres used in the petrochemical industry, to metallic fibres , from fibreglass and optical glass to polymer fibres, which comprises polyethylene, that is the most common plastic used for packaging. Fibres can be woven into textiles or deposited as nonwoven sheets to make filters, insulation, envelopes, or disposable wipes.

    In the production process of these objects and devices, the quality check of fibres plays a role of great importance, where the fibre diameter and size distribution of the fibres are the key parameters. For this step, sophisticated analysis techniques are required to ensure the fibres quality during manufacturing. For example, in the filtration industry, the quality check of the manufactured fibre textiles is of utmost importance to guarantee the filtration efficiency.

    Fig. 1 & 2: SEM images of two metal grids, using 15kV (left) and 10kV (right) beam.

    Imaging of conductive fibres: what is important?

    Conductive fibres such as metal grids can be easily imaged in a SEM without any difficult sample preparation. The specimen containing the fibres is positioned on a pin stub and then placed on a holder that can be inserted into the microscope. For high resolution imaging we recommend high acceleration voltage (10kV or 15kV) and low current, while for composition elemental analysis high current is preferred. Figure 1 shows two examples of metallic fibres in a regular grid, imaged using a 15kV (left) and a 10kV (right) beam.

    Imaging of non-conductive fibres: what is important?

    While imaging conductive samples is, in most cases, rather straightforward, in the case of non-conductive samples the sample preparation plays a crucial role in successfully acquiring informative images. In fact, the imaging in a SEM is done by scanning the electron beam on the surface of a specimen. If the sample is non-conductive, the negative charges build up on the surface, leading to a charging effect, compromising the quality of the analysis. A few different tricks can be applied during sample preparation to limit the effects of charging.

    To limit the effect of charging, insulating samples can be imaged with a low acceleration voltage and low beam current. However, with this method the image resolution deteriorates because of the low electron energy. To overcome this limitation, non-conductive fibres can be coated with a thin conductive film that allows imaging at high acceleration voltage. Figure 2 shows a SEM micrograph of a cotton cloth covered with a 10nm gold film deposited using a sputtercoater. In this example, no charging artifacts are visible and the image quality is preserved. However, because of the 3D dimensionality of fibres, in some cases the sputtered metal might not reach the underlying fibres, which will therefore charge under the electron beam.

    To avoid charging, it is also possible to image non-conductive fibres in low vacuum mode. The presence of air molecules in the microscope chamber allows the electrical charges to find a conductive path and leave the specimen surface. Figure 3 shows the SEM images of a human hair taken in high vacuum (left) and low vacuum (right), using the charged reduction sample holder. In the first image, the charging effect shows up as a brightening of the top surface of the hair, hiding the surface details. In the second image, the charging effects are eliminated by using the low vacuum mode and the surface details are now visible.

    Fig. 3: SEM image of a cotton fabric coated with 10 nm of gold using a 15kV beam.
    Fig. 4 & 5: SEM images of a human hair imaged in high vacuum (left) where charging is visible and in low vacuum (right), using the charged reduction sample holder

    Checking the fibres quality: the tensile test

    Tensile tests are also required in some production lines to check how resistant fibres are when stretched. Performing tensile tests in a SEM allows the user to check, in real time, how the fibres textile stretches under the presence of a force and how the fibres break. Figure 6 shows a strip of paper that was previously covered with 10nm of gold, being torn using the tensile stage.

    Fig. 6: SEM images of a strip of paper being stretched using the tensile stage

    As you can see, there are specific best practices for sample preparation that you can follow to obtain a high quality SEM images.

    About the author: Marijke Scotuzzi is an Application Engineer at Phenom-World, the world’s leading supplier of desktop scanning electron microscopes. Marijke has a keen interest in microscopy and is driven by the performance and the versatility of the Phenom SEM. She is dedicated to  developing new applications and to improving the system capabilities, with the main focus on imaging techniques.

     

     

    About Phenom-World

    Phenom-World is a leading global supplier of desktop scanning electron microscopes and imaging solutions for submicron scale applications. Their SEM-based systems are used in a broad range of markets and applications. They continuously invest, develop and integrate their products to help customers improve their return on investment, time to data, and to increase system functionality.

    Lambda Photometrics are the UK and Ireland distributors for sales, service and applications and have been working with Phenom-World for many years. Click here for more information alternatively please contact our Sales Engineers on 01582 764334 or at contact@lambdaphoto.co.uk.

  • Technical and Application Notes for the SRS BGA244 Binary Gas Analyser

    Stanford Research Systems BGA244

    The BGA244 Binary Gas Analyser from Stanford Research Systems (SRS) is a new product harnessing the fundamental physical principles of acoustic resonance to measure the speed of sound in a gas mixture and provide gas ratio measurements with errors as low as 100ppm. This technique has advantages over conventional thermal conductivity binary gas analysers with SRS’ implementation providing a dramatic improvement in performance and value:

    • Ten times better accuracy
    • Thousand times better stability
    • Lower cost of ownership due to reduced installation cost and maintenance
    • Greater flexibility with ~500 pre-calibrated gases and no recalibration to change gases

    To learn more about the physical principles behind the BGA244, its use in many diverse applications and the comparisons with other binary gas analysers, the following series of technical/application notes are available. Simply click on each link to download the document you require. For further information or to ask any questions, please do contact us on 01582 764334 or click here to email

    Tech Note - BGA244 Physics Overview

    Tech Note - Comparing Thermal Conductivity Analysers with the BGA244

    Tech Note - BGA244 vs Composer Elite

    Tech Note - Using Pressure Transducers with the BGA244

    Tech Note - Gases Measured by the BGA244

    Tech Note - BGA244 Diborane in Hydrogen

    Tech Note - BGA244 Measuring Mixtures of Nitrogen and Hydrogen

    Tech Note - BGA244 Long Term Stability for Measurement of Trimethylindium

    Tech Note - BGA244 High Concentration Ozone Measurements

    Tech Note - BGA244 Creating User Defined Gases

    Tech Note - BGA244 Monitoring Gas Quality in Helium Recovery Systems

    Tech Note - BGA244 Carbon Dioxide and the Relaxation Correction

    Tech Note - BGA244 Measurement of Argon-Air and Krypton-Air Mixtures for Insulating Windows

    Tech Note - BGA244 Measurement of Methane in Argon

  • Applications of Scanning Electron Microscope in Pharmaceutical Research Field

    Pharmaceutical research involves creation of new drugs or continuous improvement of existing drugs. This versatile research topic is a broad field of study dealing with an increasing number of challenges, owing to new pathogens emerging constantly and known pathogens becoming increasingly resistant to existing drugs.

    Since more information is needed, the use of advanced tools, such as scanning electron microscopes (SEMs), has been shown to be very powerful in various applications in the pharmaceutical field. In pharmaceutical research, SEMs are used for powder imaging and analysis, to gain insights into cellular interactions with new drugs, and for applications in the most complicated cancer treatments.

    This article discusses a few examples to illustrate the successful application of SEMs in research facilities across the world to develop novel and more powerful drugs to treat diseases.

    Figure 1. An example of mammalian cells observed with SEM

    Superporous hydrogels

    A research team at AIMST University in Malaysia is involved in the development of a new class of superporous hydrogel beads. Hydrogels consist of a network structure of cross-linked hydrophilic polymers that are capable of absorbing water in large amounts without dissolving.

    These beads are employed as carriers in pharmaceuticals for controlled drug delivery based on their biodegradation and swelling abilities. Since a targeted drug delivery eliminates side effects on other cells or tissues, it helps achieve easier and faster regeneration.

    With developments in research, and the increasing need to develop enhanced and highly performing drugs, the researchers have developed a new class of hydrogels with rapid swelling capacities - the reason for the name “Superporous Hydrogels”. Here, the researchers examined the surface structure and porosity of the dried beads using a SEM.

    Cancer drug research

    A new kind of approach was used in cancer drug research. It was found that aromatase, an enzyme responsible for determining the final sex phenotype of fish, was also playing a key role in the progression of breast cancer. Therefore, in a study, researchers used aromatase inhibitors for breast cancer treatment.

    In fish, androgens are irreversibly converted into estrogens by aromatase enzymes, thereby establishing the embryo’s gender to female. Researchers are showing more interest to study male fish than female fish of this species because male fish generate anti-aromatase in large quantities.

    Like Nile tilapia which gained attention as a source of food worldwide, aromatase obtained from this fish was the subject of interest for researchers looking for aromatase inhibitors.

    Nile tilapia microsomes were used to study the enzyme activity of aromatase inhibitors. They are vesicle-like fractions of the endoplasmic reticulum (ER) present in healthy living cells. In this study, hepatic microsomes were prepared from Nile tilapia and their morphology was explored using a SEM.

    The proliferation of cancer cells was investigated using HepG2 human hepatoma cells and MCF-7 human breast cancer cells. The study results revealed that the growth of both cancer cell lines was efficiently inhibited by a specific anti-aromatase present in microsomes.

    For a successful cancer research, the morphology of tissues needs to be analyzed and understood. At present, this can be achieved using the correlated light and electron microscopy technique.

    Figure 2. Correlated light and electron microscopy image of HeLa cells

    Development of antibacterial powders

    Antibiotics are excessively used and as a result, the numbers of antibiotic resistant bacteria are constantly increasing. Hence, researchers are seeking new ways to find the presence of bacteria on medical devices to prevent nosocomial infections or hospital-acquired infections as much as possible. Extensive research is going on in the development of new antibacterial powders.A study revealed that pathogens present on polymer medical appliances can be very efficiently destroyed when ZnO and Ag-ZnO crystals are added to antibiotics. Here, a SEM was used to analyze the elemental composition and morphology of the crystals before using them for further experiments.

    Figure 3. Pharmaceutical crystals observed with SEM
    Figure 4. Pharmaceutical components including crystals observed with SEM

    Conclusion

    In summary, scanning electron microscopes are a very polyvalent tool that can be used for various research activities in the pharmaceutical field. It helps understand the morphology of the component of interest and highlights the effect of interactions with its environment.

    References

    1. Development and in vitro Evaluation of New Generation Superporous Hydrogel Beads (SPHBs) Containing Fluconazol. Kumar et al. Journal of Pharmaceutical Sciences & Research; Vol. 5 Issue 12, p259 (2013)
    2. Investigation of anti-aromatase activity using hepatic microsomes of Nile tilapia (Oreochromis niloticus). Pikulkaew et al., Drug Discoveries and Therapeutics (2017)
    3. Antibacterial Powders for Medical Application Prepared by Microwave Hydrothermal Assisted Synthesis. Kunitka et al,. Nanoscience and Nanotechnology, 6(1A): 88-91 (2016)

     

    About Phenom-World

    Phenom-World is a leading global supplier of desktop scanning electron microscopes and imaging solutions for submicron scale applications. Their SEM-based systems are used in a broad range of markets and applications. They continuously invest, develop and integrate their products to help customers improve their return on investment, time to data, and to increase system functionality.

    Lambda Photometrics are the UK and Ireland distributors for sales, service and applications and have been working with Phenom-World for many years. Click here for more information alternatively please contact our Sales Engineers on 01582 764334 or at contact@lambdaphoto.co.uk.

  • How SEM helps discover suitable corrosion inhibitors

    Many industries would benefit from the inhibition of corrosion in metals. In the materials science field, scientists are therefore exploring ways to prevent or reduce corrosion. Many studies looking for suitable corrosion inhibitors have been carried out.

    However, most of the inhibitors discovered and developed during those studies were synthetic chemicals, which are very expensive, and hazardous to the environment. Due to the characteristics of these chemicals, studies were carried out to investigate and analyse natural products that could be used as an anti-corrosion agent. SEM technology helped conduct these studies in an effective manner, something we will describe further in this article.

    SEM image of speed steel

    The use of castor oil extract to inhibit corrosion

    In 2017 Omotioma et al. (Int. J. Chem. Sci.: 14(1)) describe the use of castor oil (Ricinus communis) extract to inhibit corrosion of mild steel. Morphological observations of the corroded mild steel samples were carried out using scanning electron microscopy (SEM). As a result of this study, castor oil extract was found to inhibit both cathodic and anodic reactions and act as a mixed-type inhibitor.

    Another study from the same research group in 2015 (Der Pharma Chemica, 2015, 7 (11):373-383) investigated the use of leaves extract of bitter leaf (Vernonia amygdalina) as corrosion inhibitor for aluminum. In this case, detailed changes in morphology were also revealed with the use of a SEM, which serves as a helpful tool to understand morphological changes in detail.

     

     

     

     

    SEM image of aluminum

    Corrosion behaviour on stainless steel

    A more detailed study on corrosion behaviour on stainless steel, with a focus on oil refinery distillation systems, was performed by Loto in 2016 (J Mater Res Technol. 2016). During this study, the surface morphology was analysed in more detail with SEM to detect defects or surface changes. The capability to understand surface morphology in combination with elemental detection via EDS allows results to be obtained in a fast and easy manner. The study was successful in proving that S32101 steel has significantly lower corrosion rates than 410 martensitic stainless steel used for applications in oil refinery distillation systems.

    If you would like to learn more about the potential of a SEM system paired with EDS technology, click here.

     

    About the author:Dr. Jasmin Zahn is an Application Engineer at Phenom-World, the world’s leading supplier of desktop scanning electron microscopes. She is highly engaged in finding out more about the possibilities for Phenom-World products in various applications. In addition, Jasmin is active in sharing best practices with the outside world to encourage them to look outside their standard scope of use and to improve in their work.

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