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Differential Pressure Sensor Test Platform
Summary: A piston-phone is an actuator device that can be used to calibrate pressure transducers and low-frequency microphones. This particular piston-phone was designed for the dynamic calibraiton of a differential pressure transducer over the frequency range of 0.01 to 10 Hz.
The device's software is composed of a Visual Basic GUI with two serial interfaces. The hardware consists of a container with a controllable volume, a SenSym differential pressure transducer interfaced to a Linear Technology LTC2411 24-bit analog-to-digital converter, and an Allegro UNC 5804B stepper motor control IC and a stepper motor.
The volume is adjusted using a threaded syringe. The syringe volume can be varied over a range of +/- 500 microliters. The stepper motor controls the syringe displacement, One revolution on the syringe plunger yields a volume change of 13.32 microliters, and the stepper motor can be adjusted in increments as small as 1.8 degrees. The gas volumes are thermally insulated to provide a pseudo-isothermal condition that allows Boyle's law to be used to estimate the change in ressure as a function of the change in volume.
Technologies used: MicroChip PIC assembly language for stepper motor control, Visual Basic 6, asynchronous and synchronous serial programming (SPI), Excel VBA horizontal strip chart
Client: MECH (now Sampled Systems LLC)
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Sampled Systems
31 E. 45th St.
Indianapolis, IN 46205
info@sampledsystems.com
317-361-0812