Yes. Acromag’s IntelliPack 851T load cell (strain gauge) input transmitter requires initial software configuration, but it also has front-panel pushbuttons for fast and easy adjustments in the field without a PC. Read on for the solution to a typical application.
A load cell is rated for 1000 pounds, but the actual loads will vary from a low range of 0-325 pounds to a high range of 0-475 pounds. It is rated at 2.00 mV/V with a maximum excitation of 10V DC. The desired transmitter output is 4-20mA.
The 851T transmitter is initially configured in software for an input range of 0-10mV (50% of the maximum range) and 4-20 mA output. In the field (using the pushbuttons), manually calibrating the "span" for a full scale output accommodates load ranges from 0-300 pounds (60%) up to 0-550 pounds (110%).
The IntelliPack configuration software is downloadable for demo purposes from our website. Follow along with the steps below to see how to set up the 851T for this application.
Configuring the Software:
General Properties Tab: "Input Type" = Load Cell, "Output Range" = 4-20 mA.
Load Cell Setup Properties Tab: "Excitation" = 10 VDC Internal, "Gauge Rated Output" = 2.00 mV/V.
Configuration Properties Tab: "Input for 0% Output" = 0%, . "Input for 100% Output" = 50%.
Field Adjustments (using pushbuttons):
"Zero" (minimum end of the input signal range) is adjusted between 0% and 20% of the input range to yield 4mA output.
"Span" (maximum end of the scaled input signal range) can be adjusted between 60% and 110% of the input range to yield 20mA output.
At 500 pounds, the Load Cell output is:
Excitation 10V DC x Sensitivity 2.00 mV/V x (500 actual weight / 1000 max. weight) = 10 mV.
Using 10mV as the full scale input, the Load Cell output for 325 pounds is:
(325 / 500) x 10 mV = 6.5 mV or 65% of the programmed range (60% minimum).