Product category: Pressure sensors
News Release from: SensorsOne | Subject: Pressure sensor
Edited by the Engineeringtalk Editorial Team on 12 December 2006
Pressure sensor is building
block for OEM design
OEM manufacturers of measurement instrumentation that require a pressure sensor in their product will often choose to integrate the signal conditioning within their own electronics
This enables the manufacturer to use a pressure transducer that has no signal conditioner or compensation electronics fitted. The Gefran PMH pressure transducer module has no PCB fitted to pre condition the pressure output signal, and as a result the design engineer will benefit from the natural characteristics of silicon strain gauges which have inherently good pressure hysteresis and short term repeatability due to the excellent elasticity of silicon chip diaphragms.
This article was originally published on Engineeringtalk on 12 December 2006 at 8.00am (UK)
Related stories
Data logger endures sea water
The Level Troll 500 water level data logger has excellent long-term protection against corrosion, particularly with saline liquids
Pressure data logger offers conveneience
Ad hoc applications for pressure testing new products or production machinery do not always require an elaborate data acquisition system with many input channels permanently connected to a PC
Also, since there is no conditioning electronics, the OEM design engineers are free to exploit the high natural frequency response that characteristic of semiconductor sensing elements.
The PMH pressure sensor capsule which houses the silicon sensing diaphragm is oil filled and made from stainless steel 316L.
A thin isolation membrane enables the pressure to be transmitted through the oil to the measurement sensor and provides the environmental barrier protecting the electrical connections to the silicon chip.
The pressure transducer is designed for use with a constant current power source which helps keep the thermal errors to a minimum.
Due to the high repeatability and stability of the PMH pressure sensor header it is possible to enhance the accuracy using a digital signal conditioner.
Further reading
Level transmitter resists corrosion
SensorsOne's LMK 809 submersible plastic level transmitter measures low pressure level ranges and resists corrosion
Slimline level sensors slip down boreholes
The LMP305 slimline submersible level transmitter has a 316 grade stainless steel sensor housing with a 316L stainless steel isolation diaphragm
Transducers handle high pressure testing
Hydraulic pressure test stands can be extremely unforgiving to some pressure transducers
Digital characterisation is carried out by mapping the pressure sensor over pressure and temperature.
The recorded data is then processed mathematically to derive a polynomial equation that describes the behaviour of the pressure transducer.
The polynomial equation coefficients are stored inside the measurement instruments memory and used to digitally improve the accuracy of the pressure transducer output signal.
The Gefran PMH pressure sensor has pressure ranges from 250mbar up to 30 bar gauge.
To enable the engineer to design their own electrical interface bare solder pins exit from the back of the pressure sensor capsule which are either soldered directly to a PCB, flexi film wire or individual insulated wires.
An NBR or Silicone seated o-ring provides a piston seal around the outside diameter of the flush diaphragm pressure sensing capsule which allows a mechanical engineer to integrate their own pressure connection without extending the length unnecessarily with threaded pressure adaptors.
Measuring 19mm in diameter and 10mm in height the Gefran PMH pressure transducers offers manufacturers of pressure sensors and measurement instruments a compact and high performance building block for their pressure sensing development projects.
• SensorsOne: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
Search the Pro-Talk network of sites
