Multiple Pressure Transducers

Written by: Roselius, Herb

Readout in actual psi, bars, or pascals from multiple pressure transducers (voltage or 4 to 20 ma).

A manufacturer of custom pneumatic/hydraulic systems required displays for many different pressures. In advance of an actual order, they did not know what their immediate future requirements would be. They standardized on pressure transducers with 4 to 20 mA outputs, but still required stocking meters with seven different standard ranges from 200 psi to 10,000 psi. Further complicating this, they also were required to display various units of measure such as psi, pascals, bars, etc..

Since each meter usually had to be custom calibrated for them, it seemed production was always waiting for meters, even though they had a very large number of meters in stock.

The solution was simple, they reduced inventory and always had the meter they needed in stock. They stocked only two meters a 3 ½ digit (+/- 2000 count) DPL-3E and a 4 ½ digit (+/- 20,000 count) DPL-4E. The very wide offset (ZERO) and gain (SPAN) adjustment meant they could set them to display any units they required. They did pre-adjust them in the shop using a low cost 4 to 20 mA source, but did the final calibration on the production floor allowing them to match the meter to the transducer and eliminate the transducer span and offset error also. Since the meters can be adjusted at any two points, 0 pressure being an obvious choice for one of the points, they did not have to over pressure the system, just make the adjustments at their regular tests points.

Besides reducing inventory, and improving production flow, there was the added benefit of a significant cost savings per meter from their previous source. Part of this cost savings was reinvested in standardizing on the stunning blue backlit DPL-3EB and DPL-4EB meters, thus enhancing their product’s overall appearance.

A further benefit was these meters come with a ‘PSI’ annunciator on the display which they could turn on when the pressure measurement was displayed in psi.