Application Note...

PCS400 Pressure Calibration System

Application:

Calibration of a pressure sensor assembly that is installed in a custom hospital bed

Challenge:

One of the primary requirements of the manufacturer was to find a high accuracy pressure calibrator that could perform functional testing on pressure sensor assemblies with full scale ranges less than 2 psig. The pressure assemblies are used to measure the pressures in special mattresses that have zone bladders that can be adjusted to various pressures. The bladders are designed to provide "pressure-relieving distribution" for the whole body. The mattress surface includes up to six dynamic independent zones that utilize variable load displacement to contour the surface around the patient, especially body prominence, to more evenly distribute interface pressures across the body. The "smart" mattress provides pressure management by automatically sensing the variable load displacement and adjusting the zones for optimal weight distribution across all body parts. Applications for these special hospital beds include both short term and long term preventive care for bed sores (ulcers). Since these beds are classified as medical electrical equipment, the manufacturer has to comply with several standards, including UL, CE and IEC. They also have a quality system that is certified to ISO9001/EN46001.

Solution:

Since the PCS400 is available in pressure ranges as low as 0.18 psi full scale, Mensor was able to provide this medical manufacturer with a low pressure calibrator that met and exceeded their accuracy requirements. The pressure sensors, that are part of the mattress pressure management electronics, are functionally checked at the board level to insure that all specifications are met. A secondary use of the PCS400 is to calibrate and check other pressure gauges and devices in the plant.