Monthly Archives: November 2013

Selecting the Best Validyne Carrier Demodulator

Carrier Demodulator

A carrier demodulator is the electronics that supports a variable reluctance pressure transducer. A carrier demodulator provides power to the transducer, provides calibration adjustments, receives the AC sensor signal and converts it to a useable output. What is the best carrier demodulator to use with your variable reluctance pressure transducer? The answer to that question depends on a number of factors.


Do you need a digital display in units of pressure? The CD23 provides an LED display which can be read from several feet away. The CD379 has a liquid crystal display. If a digital display is not needed, then the basic CD15 is probably sufficient.


Is 110 VAC available? Most Validyne carrier demodulators have a version that will run on standard 110 VAC power. For portable use, the CD379 is battery operated.


Looking for the lowest cost? The CD101 is a carrier demodulator circuit board. Add your own
enclosure and power supply for a custom solution.

High Gain:

The CD12 provides selectable gain settings up to 20 times higher than the standard demodulator.  Combined with the zero suppression feature, the CD12 allows observation of small pressure variations that are riding on high static pressures.


If you have several transducers, then a multi-channel carrier demodulator such as the CD280 or MC1 system may be the most cost-effective carrier demodulation.

Computer Interface:

Do you want the signal to go into a PC? The CD17 is a USB interface for a single variable reluctance sensor.  Up to 16 variable reluctance transducers can be supported by the UPC2100 PCI plug-in card or the USB2250 for USB interface to laptops. These card include complete carrier demodulation and A/D conversion as well as scale and offset factors for conversion into engineering units.

carrier demodulatorFind data sheets and instruction manuals on the products listed above demodulator

Guide to Bolt Torque Validyne Pressure Transducers and Sensors

Variable reluctance pressure transducers may be disassembled and the range changed by installing a new sensing diaphragm. When changing diaphragms, the correct body bolt torque is extremely important to performance.

The sequence for torquing the body bolts is just like putting the wheel on a car. Try to apply the torque in stages. Do not torque one bolt fully while the others are still loose.

Here is a listing of the bolt part numbers and correct body bolt torque settings, by transducer model number:

bolt torque


Here are the tools needed:

bolt torque

Validyne offers a wide array of Pressure Sensors and Pressure Transducers. Feel free to contact us for more information on any of these products to fit your application.