Closed-loop control of force usually is accomplished by using a pressure transducer to monitor hydraulic pressure. But you can’t use just any pressure transducer in most hydraulic systems. Valves shifting suddenly can cause pressure spikes that occur for only a fraction of a second, but may be several times that of maximum operating pressure.
These spikes can quickly destroy any transducer not designed and constructed to withstand the rigors of hydraulic systems typically used in mobile and industrial equipment. Furthermore, pressure pulsations from pumps may not be as severe as pressure spikes, but transducers can die a slow death after prolonged exposure to continual pulsations.
The latest weapon in the battle against premature pressure transducer failure has just been introduced by Kavlico, a business unit of Custom Sensors & Technologies, Moorpark, Calif. The company’s newest sensors have been designed to perform in a wide variety of hydraulic applications. Capable of operating for millions of pressure cycles, these low power consumption sensors provide an accurate, reliable, and stable signal over many years of operation in the harshest environments. The sensors’ high overpressure capability allows them to withstand the pressure fluctuations often associated with fluid power applications.
The transducers consist or two series, the P4000 and the P250/251. The P4000 series handles pressure ranges from 0-100 to 0-6000 psi and incorporates piezoresistive sensing technology for stable output. P250 transducers are rated in bar and accommodate pressure ranges from 0-400, while the P251 is rated in psi and handles ranges from 0-100 to 5000 psi. Both provide ratiometric output that is proportional to applied pressure.
All have stainless steel housings and can be configured with a broad selection of port configurations and electrical connectors to accommodate the application. Operating on 5 Vdc, the sensors provide a 0.5 to 4.5 linear amplified output proportional to pressure. Output accuracy —the sum of linearity, repeatability, and hysteresis at 25° C — is 0.50%.
Typical applications include:
• hydraulic systems in all types of onand off-highway equipment,
• material handling systems,
• hydraulic tools and systems,
• material testing machines, and
• adaptive suspension systems.