Transducers are widely used in measuring instruments to convert a signal in one form of energy to another form of energy. The devices that typically make use of ashcroft transducers are the pressure sensors that detect pressure to convert it to electricity that can be displayed in a remote gauge. However, the ashcroft transducers are not limited to pressure measuring devices because they are also used for energy types that include mechanical, electrical, electromagnetic, chemical, acoustic or thermal energy. One example of the ashcroft transducers is the H2 pressure transducer that is ideal for measuring and controlling challenging hydraulic and pneumatic conditions. The high accuracy and performance combined with rugged construction provides a highly reliable and safe sensor platform.
How the ashcroft transducers work
The conversion of pressure into an electric signal works through the physical deformation of strain gages which are bonded into the diaphragm of the pressure transducer and wired into a Wheatstone bridge configuration. Pressure applied to the pressure transducer produces a deflection of the diaphragm which introduces strain on the gages that will produce an electrical resistance change proportional to the pressure. Ashcroft transducers / transmitters are designed for ranges of 0-5 psi through 0-20,000 psi to include vacuum/compound ranges and differential pressure ranges from 0-100to 0-300 psid. The Ashcroft transducer can be used on off-road equipment, construction machinery, compressor control, HVAC and refrigeration, agricultural implements, process automation and control, hydraulic and pneumatic sensing and pressure monitoring.
Differentiating a transducer from a transmitter
Transducers
Transducers are voltage-output devices which are used for simple signal conditioning but are considered to be more sensitive to electromagnetic interference. The electrical resistances of the connecting cable can result to significant errors if the cable is long which requires 3 or 4 connecting wires to supply power and deliver the output signal. General-purpose ashcroft transducers are designed to fit the broadest set of industrial applications while the heavy duty ashcroft transducers are designed to accommodate heavy industrial applications and tough OEM applications.
Transmitters
Transmitters are current-output devices that consist of 2 or 3 wires used to receive power and transmit an output signal. They are frequently scaled to vary from 4mA to 20mA as the pressure varies from minimum to maximum. The transmitters are more suitable for use with long cables and are much less susceptible to electromagnetic interferences. It is also more cost effective to use long cables with transmitters. Heavy industrial pressure transmitters are used on test stands, compressor control, hydraulic systems, process automation, pump and pneumatic systems controls. Safe and non-incentive pressure transmitters are used in oil field equipment, upstream oil and gas production, natural gas compression and transfer control as well as alternative energy projects.
The general rule of thumb is that if the pressure sensor has a millivolt (e.g. 30mV or 100mV) or non-amplified output it is a pressure transducer while if the pressure sensor has a voltage of (e.g. 0-5Vdc, 0-10Vdcor 1-5Vdc) output it is an amplified voltage output pressure transducer. If the pressure sensor has a current loop output (e.g. 2wire 4-20mA or 3wire 0/4-20mA) it is a pressure transmitter.
