Interfacing to Offset IF Radar Altimeter
Interfacing to Offset IF Radar Altimeter Customer Case The customer is using an offset IF radar to map forest terrain density. The equipment will be mounted in an aircraft, which will also be carrying a Global Positioning System (GPS) for reference. The plane will fly at an altitude of 10,000 feet. A 512 ns radar pulse will be sent out and a return pulse will be received about 20 uS later, from which 10,000 samples will be acquired. After the pulse is received, there will be a relatively long re-arm time of about 250 to 300 uS for the [...]
Glass Thickness
Glass Thickness Consumer Electronics Glass Thickness Thickness Description Did you know that glass thickness can be measured with a capacitance probe? You will need some equipment: Digital Accumeasure D200 ASP-2500-CTA Dielectric probe (The capacitance probe has a sensing area of 11.25 mm) Range extension = 3X, 10Hz filter Introduction:  An industrial glass fabricator needed a way to determine the thickness of glass, before cutting it to shape and coating it. The glass sample was marked with indices to find the measuring points. The sample center point -5- thickness was checked with [...]
Trigger Out Modification for CP500 Class Boards
Trigger Out Modification for CP500 Class Boards Customer Case Many A/D applications including Ultrasonics, Radar, Lidar, Hard Disk testing and CCD capture require maximal synchronicity between a trigger and the sampling clock. GaGe Case Solution GaGe now offers the TRIGGER OUT option as a means of synchronizing systems to the sampling clock on GaGe's CP500-class of A/D and scope cards, including CS8500, CS12100 and CS1250. The need for synchronicity can be understood by considering a typical ultrasonic pulse-echo system. An ultrasonic pulser-receiver generates ultrasonic pulses from a transducer which, microseconds later, receives echo signals reflected from a test specimen. [...]
Piezo Stage Positioning
Piezo Stage Positioning Consumer Electronics Piezo Stage Positioning Description Positioning stages using piezoelectric stack actuators (PEA) have very high resolution. However, it is difficult to achieve precise dynamic motion tracking using traditional linear controllers such as PID due to the inherent hysteresis nonlinearity of piezoelectric materials and the phase lag associated with such controllers. Capacitance Sensors are ideal for measuring the actual piezo stage position and correcting for the inherent nonlinearity through closed loop feedback. They have the stability, bandwidth and high resolution needed to do the job. Several of MTI’s [...]
Thread Checking
Automotive Thread Checking Presence/Absence Description Manual thread inspection is slow, not always reliable and tedious for the inspector. Manufacturers have struggled to come up with ways to reliably automate the process at a reasonable cost. Automated systems are available that use “screw sensors” can quickly wear or be cross threaded, requiring operator attention and a tooling change. A worn screw can provide false rejections leading to the unnecessary scrapping of parts. Capacitance solutions are cost effective alternative which are becoming increasingly popular due to their high reliability and fast measurement speed. Special cylindrical “ring [...]
Spindle Run Out
Spindle Run Out Automotive Spindle Run Out Distance Description Rotating targets frequently have an intermittent, uncertain or nonexistent ground path. This introduces unwanted noise, instability, drift and reduces accuracy of the measurement. MTI Instruments offers a unique "Push-Pull" capacitance measurement system that does not require a grounded target. It utilizes two probes, built into one body, that work together to complete the ground path. One probe pushes current into the brake rotor while the adjacent probe pulls the current out. The result is a "clean", consistent electrical sensing path. As [...]
Monitoring Critical Variables
Monitoring Critical Variables Customer Case The customer wanted a quick visual inspection of many readings of slow varying parameters. Readings of pressure, temperature and voltages had to be compared with reference values and the differences had to be displayed in analog fashion in the form of a simple visual display. A Go/No Go decision had to be reached almost instantly. GaGe Case Solution The solution suggested by a major electronics company was to multiplex the differences 32 readings a channel for two channels, this gives a total of 72 reading in one display. The zero line is the no [...]
Grinding Process
Grinding Process Automotive Grinding Process Surface Description A cylindrical grinding process finishes most wheel spindle surfaces. It is essential that this grinding process leave a surface finish that is smooth and free of defects with minimal runout. No grinder produces a perfect surface. Grinder wheel runout, improperly dressed wheels and fixture vibrations can cause chatter on the spindle surface finish. Chatter is a series of microscopic, repetitive imperfections, or waves, in the surface of the material being machined. The required production environment sensor must have small spatial resolution, high frequency [...]
Hopkinson Bar Testing (Stress Pulse Reaction Testing)
Hopkinson Bar Testing (Stress Pulse Reaction Testing) Customer Case This customer is involved in testing materials for how they react to stress pulses. The idea is to introduce a stress pulse into the Material Under Test (MUT) and monitor it as it travels through the material. This method of material characterization is also known as "Hopkinson Bar" testing. Multiple sensors pick up the reaction of the material and provide outputs which need to be digitized. These outputs are transient signals of approximately 2 Volts and have a rise time of approximately 600 nanoseconds. The resulting system must be programmable [...]
Oil Film Thickness Measurement
Oil Film Thickness Measurement Marine Automotive Oil Film Thickness Challenge Oil Film Thickness Measurement for Marine Engine Applications A leading marine engine manufacturer approached MTI Instruments to design and develop a non-contact oil film thickness measurement sensor capable of accurately measuring the microscopic oil film layer between the engine cylinder wall and the piston ring. This critical measurement is vital for engine performance testing, typically conducted across a wide RPM range (400 to 6000 RPM) with piston linear speeds reaching up to 500 inches/second and various torque settings. For this application, [...]