Model B12-71 Wet Hydrogen Gas Transmitter
O & M Manual
- 14 -
Rev-D, 7/15
HYDROGEN SENSOR ASSEMBLY
The % hydrogen sensor supplied with the B12-71 is shipped dry. It will not operate until it is
prepared by adding electrolyte and a membrane. Preparation of the sensor for operation must be done
carefully. The procedure should be done by a qualified technician, and it should only be done when the
system is ready for operation. Until then, it is best to leave the sensor in the condition in which it is
received.
FILL SCREW (92-0048)
Figure 11 - % Hydrogen Gas Sensor Assembly (ATI-0290)
Follow the procedure below to prepare the hydrogen sensor for operations:
1. Unscrew the electrolyte canister from the assembled sensor and also remove the vent screw from the
side of the sensor body.
2. Remove the membrane cap from the bottom of the canister and discard the protective membrane. O-
rings are contained in grooves on both the bottom and top of the canister. Be sure that these o-rings
remain in place.
3. From the package of membranes supplied with the sensor, place a new membrane into the
membrane cap.
The membrane is clear and is separated from other membranes by a paper
spacer.
4. Screw the membrane cap on to the canister until you feel the o-ring compress. Hand tight
compression is all that is needed. Do not use tools to tighten. The membrane should be flat across
the bottom of the canister without wrinkles.
5. Fill the canister with electrolyte until the level reaches the bottom of the internal threads.
CAUTION: The electrolyte used in the hydrogen sensor is very acidic. Avoid skin contact or any
contact with eyes. If contact occurs, flush with large amounts of water.
