Tech Note 123: Calculating Transmitter Ranges
Last Updated: 05/11/2017
STI’s CMCP500 and CMCP700S Series transmitters and monitors are calibrated for the most common industry standard sensors such as 100mV/g accelerometers and 200mV/mil eddy current probes though we do provide custom calibration on request. Frequently we get requests for transmitter or monitor configurations for inputs other than our factory defaults. Our default calibrations allow the user to use a common number when programming their PLC or DCS system but since the output range stays proportional with the input signal our transmitters and monitors can easily be used with non-standard inputs such as 30mV/g or 50mV/mil sensors.
The actual full scale range can be achieved by using the following formula;
(Ci/Ai) * Cr
Where: Ci = Calibrated Input Sensitivity
For Example, a transmitter calibrated for a full-scale output of 1.0 In/Sec with a 100mV/g input and an actual input of 25mV/g the following formula would apply;
(100/25)*1 = 4.0
Thus meaning the transmitter would have a full scale range of 4.0 In/Sec with a 25mV/g input.
In/s to mm/s: In/sec * 25.4 = mm/s (ex. 2.0 in/s * 25.4 = 50.8mm/s)
The following tables may be used to quickly identify the transmitters range with a given input sensitivity. Items in red show the factory default inputs and ranges. Take note that the CMCP500 and CMCP700 Series have up to 5 selectable range which simply double, triple, quadruple and quintuple the first range option.