Installation for the Pathfinder CT-1000-100PPM-K0.1 Conductivity Transmitter

Installation for the Pathfinder CT-1000-100PPM-K0.1 Conductivity Transmitter

The CT-1000 is intended for use with 3-wire temperature-compensated sensors or 2-wire conductivity only sensors. The Model CT-1000 miniature transmitter is a 2-wire, 4-20 mA / 1-5 VDC conductivity transmitter featuring epoxy encapsulated construction, high performance, RoHs compliance and small physical size.


  1. Two 6-32 mounting holes 9” centers are provided. The transmitter can be mounted in a
    head, weather-proof box, or DIN rail.
  2. The output wires are isolated from ground; connections are made at the terminal strip
    observing polarity to the terminals marked + , -out. These wires are to be connected to a
    DC power supply through a load resistor. The wires can be as long as necessary.
    Connect the ground terminal to earth ground.
  3. The loop resistor can be either in the positive or negative power supply lead. The value
    of the loop resistor depends on the voltage required at the monitoring location. Calculate
    the required power supply voltage from the following equation:
    minimum Vpower supply = 12 + (0.02 x Rloop)
    A convenient value for the loop resistor (Rloop) might be 250Ω and so the minimum power
    voltage would be:
    minimum Vpower supply = 12 + (0.02 x 250) = 17V DC
    The maximum supply voltage is 36V DC.
  4. Connect sensor to transmitter by matching wire color to designated color on terminal
    block (i.e. electrode’s red wire to terminal block “RED”, …)
  5. Turn the unit on end with the conductivity cell in the air and adjust the “ZERO” to an
    output current of 4.00mA
  6. Put the conductivity cell in a conductivity solution that exceeds the highest expected
    value and adjust “SLOPE” to an output current of 20.00mA
  7. SPECIAL NOTE: The transmitter is supplied with a 10K resistor in place of where the
    temperature compensation can be connected. Leave the resistor in place if your
    electrode does not have temperature.
    Contact us for more information.

Pathfinder Instruments

21955 Plummer Street
Chatsworth, CA 91311

Hours of Operation

9:00 AM – 5:00 PM PST