CR-421 is a simple and accurate stationary device used for continuous redox and temperature measurements in clean water or sewage.
Depending on working conditions, the appropriate type of redox electrode may be chosen and built-in the flow through or immersible head.
The controller is available in three versions:
1. Equipped with two relays to control valves and signalisation system.
2. Equipped with 0 ÷ 20 mA or 4 ÷ 20 mA current loop.
3. Equipped with RS-232 output with a software to collect the data on a PC. Optionally, the connection may be made by USB with use of RS-232 / USB converter (additional equipment).

  • High accuracy at an affordable price.
  • Meter is equipped with backlit LCD display.
  • Periodically, the sensor should be manually cleaned.
  • Powered with 12 V power adapter.
  • Quick warranty and after-warranty repair service.

  • CR-421 is equipped with a hanger for mounting on a wall.
    In case, when the distance between the sensor and the controller exceeds 10 m, it is necessary to use an additional preamplifier mounted in the immersible head or next to the flow head.

    Function Redox Temperature
    Range ± 1999 mV -50.0 ÷ 199.9 °C
    Resolution 1 mV 0.1 °C
    Accuracy (±1 digit) ±1 mV* ±0.1 °C**
    Input immpedance >1012Ω -
    Relay's parameters 2A/250VAC/30VDC
    Radio electric interference N level
    Power supply 12 V / 100 mA power adapter
    Weight 210 g
    Dimensions (mm) L = 149, W = 82, H = 22
    * The accuracy of the meter only.
    ** The accuracy of the meter only. The total error includes the meters and probe’s accuracy. In the range 0 ÷ 100 °C the acceptable error of the probe with Pt-1000B resistor: ±0.8 °C, with Pt-1000A resistor: ±0.35 °C.