H2-CNI I2C-I FWB-A

Features:

• Detection of hydrogen levels up to 12 vol % with 100 ppm resolution in air

• Industrial temperature range from -40 °C to +85 °C

• Ultralow thermal drift

• No sensitivity against typical catalyst poisons such as volatile siloxanes and carbon monoxide

• Fast response and recovery times

• No humidity-induced base line drift

• Applicable in relative humidity (rh) between 0 % to 100 %

• Linear output

• No cross-sensitivity against hydrocarbons such as methane and ethane

• Full Wheatstone bridge (FWB) configuration, including a digital rheostat with a nonvolatile memory for offset adjustment

• Available as advanced version FWB-A and basic version FWB-B with adjustable precision voltage source for bridge 

H2-CNI I2C-I FWB is a calorimetric hydrogen sensor with a catalytically highly active and siloxane-resistant sensor element and is based on a non-isothermal calorimetric operation principle. It is fully digital with digital conversion of the sensor signal and it contains a digital temperature sensor and an EEPROM for an advanced control of sensor characteristics in a wide temperature range of -40 to +85°C.   As a result of high-precision adjustment, the thermal drift of the zero signal is very small.  

Pin 1 Midpoint of the 2nd 

branch of the Wheatstone bridge (can 

remain unconnected) 

Pin 3 SCL line of I2C bus 

Pin 4 Bridge excitation voltage connected to 1st junction of the active sensing element, can be connected to VPOW if a single supply voltage is used (FWB-B only). Otherwise, a positive voltage with respect to AGND must be applied. Leave unconnected for FWB-A sensors. 

Pin 5 Junction between active sensor element and reference element (can remain unconnected) 

Pin 6 1st junction of reference element, must be connected to AGND

Pin 7 I2C ground 

Pin 8 SDA line of I2C bus

Pin 9 Supply voltage of internal 

electronics.