Senior Product Manager Chris Gibson discusses differential signaling and measurements, and more, in a joint webinar with Anritsu.
Thermocouples are without a doubt the most popular type of temperature sensor, and the VTI Instruments EX1000A Precision Voltage Measurement Instrument Series provides 48 voltage channels and supports Type J, K, T, E, S, R, B, and N thermocouples. To help you avoid some common pitfalls when making thermocouple measurements and get the most out of your instrument, we offer the following tips:
When accuracy really counts, you should make four-wire resistance measurements. Sometimes referred to as the Kelvin method, the four-wire resistance method is often used in automated test applications where long cable lengths, numerous connections, or switches exist between the digital multimeter (DMM) and the device under test (DUT).
To maintain signal integrity in an automatic test system requires:
Many accelerometers used for measuring vibration include a built-in preamplifier to transform the high impedance charge output of the piezoelectric sensor into a low impedance voltage signal, typically 100-300 ohms, that can be transmitted over longer distances. To power this preamplifier, many VTI Instruments products provide an interface that complies with the Integrated Electronics Piezo Electric, or IEPE standard. Using this standard interface ensures that you can connect sensors with an IEPE interface to a VTI instrument and get good results.
When performing functional tests, keeping test times as short as possible is often a critical requirement. Time is money, after all. One way to reduce test times is to reduce the latency in setting up signal switch paths, stimulus devices, and measurements. These can all have a significant impact on the overall time it takes to complete a full functional test of a particular DUT.
Calibration is not an option. While today's instruments are more accurate and drift less than previous generations, you still need to periodically check and calibrate your equipment. The way you do this, however, is changing.
In the past, manufacturers would recommend calibration intervals. A digital multimeter manufacturer might, for example, recommend that you calibrate the instrument once a year. When that year was up, you sent the DMM to your company's cal lab or to a third party.
That paradigm is changing. The current trend in metrology is not to blindly follow a manufacturer’s stated calibration interval, but to determine your own interval based on how much each instrument drifts over time and how much risk you're willing to take.
VTI Instruments' new RX0424 IEPE/Voltage Instrument is a cost-effective new device that is ideal for measuring acceleration forces and sensing static and dynamic movement or vibrations. Fully-integrated IEPE current excitation and tachometer input channels further enhance the instrument’s utility and functionality.
The automotive market is a highly competitive and complex business. In order to be competitive, vehicles must not only offer comfort and top-notch features at a cost-effective price but also ensure passenger safety. Long before any new model goes into mass production, a long series of sophisticated tests and validations are required at various stages to ensure that the vehicle meets all governmental standards and company performance standards.
Vehicles are often operated under test conditions for weeks or months, which requires logging and archiving massive amounts of data. In addition, in-vehicle tests often require the use of portable test systems, which are ideally compact, rugged, light in weight and free standing. Given the limited space within the vehicle, they typically must operate wirelessly with no connection to a computer. These in-vehicle datalogging systems must be compatible with a wide array of sensors.
A jet engine is the very definition of “mission-critical.” A critical failure could cause a serious accident that endangers hundreds of lives. To prevent this from happening, manufacturers perform extensive testing on jet engine components, systems, and manufacturing processes.
Jet engine tests involve subjecting the unit under test to extreme temperatures, jets of water, simulated hail, severe vibration, and other harsh conditions. Sometimes test engineers even slam chicken carcasses against engines to simulate bird strikes. These tests can be very costly and take years to develop. Engineers must measure many different parameters during these tests, including temperature, flow, pressure, rotation, strain, and vibration.
