Radar Tester

G/T is referred as figure of merit of the RF antenna. G stands for Antenna gain and T stands for Antenna noise temperature. This is most often asked in the interview for satellite group position.

High frequency sound waves are very directional, and they will travel through a medium (like a piece of steel or plastic) until they encounter a boundary with another medium (like air), at which point they reflect back to their source. By analyzing these reflections it is possible to measure the thickness of a test piece, or find evidence of cracks or other hidden internal flaws.

Important parameters relating to vibration pickups/vibrometers are described below: (1) Vibration frequency Unit: Hz (Hertz) Symbol: f Refers to the number of times a vibrating object vibrates per second. The inverse of a vibration frequency is referred to as the period (T), T=1/f.

Vibration analysis can help diagnose many issues ranging from improper lubrication to electrical defects. Some of the most common issues found are: Roller bearing defects, Equipment imbalance, Coupling misalignment, Looseness, Resonance, Gear defects, etc.

GPR is extremely accurate when it comes to locating metallic and non-metallic objects. GPR systems work by sending a tiny pulse of energy into the ground from an antenna. An integrated computer records the strength and time required for the return of reflected signals. Any subsurface variations, metallic or non-metallic, will cause signals to bounce back. When this occurs, all detected items are revealed on the computer screen in real-time as the GPR equipment moves along. Users can even tell from the signal returned whether the feature in question is metallic or non-metallic.

Yes. GSSI’s systems can integrate with most GPS systems. The GPS position data files and GPR scans are automatically matched within our systems so that the resulting data shows proper GPS position.

The term Wavelength is basically distance from wavecrest to wavecrest along direction of travel of EM wave. The unit is centimeter.

Some interviewers like to see your reactions to whacky questions like, “If an elephant walked into this room, what would it say?” There is no right/ wrong answer to this one. The interviewer is looking for quick thinking, an ability to handle unprepared situations, a calm demeanour and even a sense of humour. Don’t go overboard on the humour or sarcasm though. Avoid statements that convey negativity or desperation.

Bistatic radar has two antennas; one for transmission and the other for reception. These antennas either located side by side or they are located far away.

While GPR is in use with many professional mining companies, the technology is not well suited to finding coins, gold nuggets or buried treasure. Metal detectors are more suitable. GSSI recommends checking with local, state and federal laws before beginning any treasure-hunting activities.

Ground Penetrating Radar is also known as GPR, Ground Probing Radar, Ground Radar, and Georadar.

Several factors such as equipment runtime, criticality, running environment conditions, etc. help determine how often vibration needs to be performed. On equipment that runs year round, quarterly vibration analysis is recommended as a minimum frequency. However, many manufacturing environments require monthly vibration analysis on critical machinery.

Accelerometers are instruments for measuring, displaying, and analyzing acceleration and vibration. Vibration sensors cover sensors and other instruments used for measuring vibration and acceleration.

Sound waves traveling through a material will reflect in predictable ways off of flaws such as cracks and voids. An ultrasonic flaw detector is an instrument that generates and processes ultrasonic signals to create a waveform display that can be used by a trained operator to identify hidden flaws in a test piece. The operator identifies the characteristic reflection pattern from a good part, and then looks for changes in that reflection pattern that may indicate flaws.

Ultrasonic flaw detection requires a trained operator who can set up a test with the aid of appropriate reference standards and properly interpret the results. Inspection of some complex geometries may be challenging. Ultrasonic thickness gages must be calibrated with respect to the material being measured, and applications requiring a wide range of thickness measurement or measurement of acoustically diverse materials may require multiple setups. Ultrasonic thickness gages are more expensive than mechanical measurement devices.

The pair of frequencies which produce the same output at the output of the RF receiver are referred as images of each other. For example in C-band satellite receiver, 3700MHz and 5785 MHz produce the same 70MHz as output. Hence here 5785MHz is the image frequency for 3700MHz and vice versa, Refer RF measurements tutorial to know more about this and other RF measurements. Homodyne and heterodyne are the two main architectures used in RF receiver. Refer heterodyne receiver vs homodyne receiver to find the difference between them.

For equipment that is difficult to access while it is in operation, MTI can either temporarily or permanently mount sensors to easily take readings on the equipment.

Both return loss and VSWR is used as a measure of reflection of E-M waves over coaxial cable or RF cable or microstrip line. It gives how much power is reflected and how much power is absorbed at various points specially at terminating and source points and at places of impedance discontinuities. Return Loss in a coaxial cable having Z0 as characteristic impedance and ZL as terminating or load impedance can be expressed as follows:

Return Loss (dB) = 20*Log10((ZL-Z0)/(ZL+Z0))

Where Z0= (L/C)0.5

Both Return loss and VSWR are related as mentioned in the following expression.

Return loss = 20 log ((VSWR+1) / (VSWR-1))

VSWR ranges from 1 to infinity.