H2-CNI 4-20mA-I
Features:
- Accurate detection of hydrogen levels up to 100% LEL with 100 ppm resolution in air
- Negligible sensitivity against typical catalyst poisons such as volatile siloxanes and carbon monoxide
- Fast response and recovery times
- Negligible humidity-induced base line drift
- Applicable in relative humidity (rh) between 0 % to 100 %
- Industrial temperature range -40 °C to +80 °C
- Linear output up to 100 % LEL
- Available with ultra-low thermal drift (ULTD) and test protocol
- 4-20 mA current-loop transmitter with reverse voltage operation and over-voltage surge protection
- Supply voltage with reversed bias protection
- Designed for many years of operation time
H2-CNI 4-20mA-I and H2-CNI 4-20mA-I ULTD are four-pin calorimetric hydrogen sensors with a catalytically highly active and siloxaneresistant sensor element and is based on a non isothermal calorimetric operation principle. The sensor contains on-board electronics to reduce the effect of ambient temperature changes on hydrogen sensitivity, featuring a secure 4-20 mA current interface. It is designed for use in a variety of applications which require accurate hydrogen determination in air. The sensor can be operated without connecting the I2C bus.
Pin 1 +12 V positive supply voltage with respect to ground
Pin 2 Current output connect to 0 V of the current loop
Pin 3 Ground of the internal electronics. The pin is electrically not connected to the housing
Pin 4 Current input connect to +24 V of the current loop*
SCL Clock line of the I2C bus**
SDA Data line of the I2C bus**
* The current loop must be galvanically decoupled from the 12 V supply voltage. No common mass is allowed. The current loop must contain a driving voltage source (recommended value: +24 V).
**If connected, provide necessary pull-up resistors to SCL and SDA (e.g. 4.7 kOhm).