Knowledge Base:  
Tech Note 123: Calculating Transmitter Ranges
Last Updated: 05/11/2017

Calculating Transmitter RangesSTI’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
Ai = Actual Input Sensitivity
Cr = Calibrated Range

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 addition, English ranges may be converted to Metric by using the following formulas;

In/s to mm/s: In/sec * 25.4 = mm/s (ex. 2.0 in/s * 25.4 = 50.8mm/s)
mils to microns: mils * 25.4 = microns (ex. 15 mils * 25.4 = 381 microns)
mils to mm: mils * 0.254 = mm (ex. 10 mils * 0.0254 = 254 mm)

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.

Was this article helpful?


Related Articles
 > Tech Note 101: Wiring CMCP1100 (ICP) Accelerometers
 > Tech Note 102: Powering – 24 VDC Eddy Probes
 > Tech Note 103: Accelerometer Powering with CCD Diode
 > Tech Note 104: Wiring Relays with Common Alarms
 > Tech Note 105: Reversing Normal Thrust Direction CMCP545(A)
 > Tech Note 106: Recalibrating CMCP505 Digital Displays >01/01/07
 > Tech Note 108: Installation of Accelerometer Extension Cables
 > Tech Note 107: Recalibrating CMCP505 Digital Displays <01/01/07
 > Tech Note 109: Troubleshooting 500 Series Transmitters
 > Tech Note 110: Troubleshooting CMCP420VT(T)
 > Tech Note 111: CMCP510 Display Calibration
 > Tech Note 112: Vibration Severity Level ISO 10816-1
 > Tech Note 113: CMCP420VT(T) Compliance
 > Tech Note 114: Double Integration of Vibration Signals
 > Tech Note 115: Shunt Resistors
 > Tech Note 116: Electro-Mechanical Velocity Sensors
 > Tech Note 117: ISO Standard 10816-3
 > Tech Note 118: What We Need to Know!
 > Tech Note 119: CMCP420VT Buffered Output
 > Tech Note 120: CMCP575 Tachometer Precision Calibration
 > Tech Note 121: Magnetic Bases for Accelerometers
 > Tech Note 122: Double Integration
 > Tech Note 124: Cable Grounding (Isolated and Non-Isolated Shields)