Understanding Facts about Resistivity Transmitters

General Description of Pathfinder HPT12 Resistivity Transmitter

The Model HPT-12 (encapsulated transmitter) is a 0-1.2 volt Resistivity transmitter with an input range of 0 to 12 megohm/cm and an output of 0 to 1.2 volt, using an RC-20 probe for an input.

The transmitter accepts as its input an RC-20 resistivity cell which has a .007 cell constant and an integral temperature sensor for automatic temperature compensation. It transforms the probe signal to a voltage output proportional to the resistivity level. This output may be transmitted over two wires to a voltage indicating device. A D.C. power supply of 24V is required to power the transmitter.

There are two adjustments on the transmitter to calibrate “ zero” and “span”. The calibration is performed using a resistor module Model: RM-HP12

HPT-12 Specifications
Range: …………………………………………………………………0.00 to 12.00 Megohm/cm
Output: ………………………………………………………………..0.00to 1.20V
Power Supply: ………………………………………………………..24 V DC
Accuracy: ……………………………………………………………..+/- 2% of span
Resolution: ……………………………………………………………û .01 Megohm/cm
Resistivity cell: ……………………………………………………….Resistivity Ptobe: Pathfinder P/N: RC-20
Operating Temperature Range: …………………………………..0 to 50 deg C
Temperature Compensation range: ……………………………. 10 to 60 deg C
Calibration: ……………………………………………………………Resistor module to 1.2 volt output (Pathfinder P/N: RM-HP12 )
Dimensions: …………………………………………………………..2" X 2" X 1.5"
Mounting: ……………………………………………………………..(2) 6-32 threaded inserts, on 0.9” centers