Application Note...

PCS400 Pressure Calibration System

Application:

Calibration of pressure transducers and pressure switches in calorimeter test cells for refrigeration systems. The plant is the primary research and development facility for this global HVAC manufacturer. The refrigeration systems are installed in trucks, trailers, buses, railcars and containers on ships.

Challenge:

To provide a convenient, easy to use and very accurate pressure calibration system that can be used in any of the test cells in the plant.

Solution:

A Mensor PCS400 Pressure Calibration System, mounted on a portable cart, was purchased for the secondary plant standard. The PCS400 and a portable data logger were mounted upon a cart. This "pressure cart" was used in conjunction with a computer and associated peripherals that were installed in a separate console to provide system flexibility.

The typical test cell has six pressure transducers that must be calibrated on a semi-annual basis. One transducer is used to measure the compressor low pressure (150 psia), another is used to measure the high pressure (500 psia) and others measure other "system" pressures. All pressure transducers are "hard-mounted" in the test cell and only removed if there is some mode of failure. So the calibration procedure must be performed in the individual test cells per the approved company procedures.

This particular customer is ISO9000 and has many plants worldwide. Quality is a very focus of this HVAC company and appropriate secondary standards and procedures are used to insure quality and customer satisfaction.

The PCS400 pressure range was chosen to cover all the ranges of the typical transducers in every test cell. Reliability and ease of use was an important consideration to the customer. The PCS400 is used both in the local (manual) and remote modes of operation for pressure calibration. The customer wrote the necessary programs to interface with the instrument over the IEEE bus (GPIB).