MSA 5100-03-IT, Operating Manual

Page: 63 / 68

6. Electrolyte Replacement
a. Invert the sensor assembly so that the membrane is upward.
b. Insert the sensor assembly in a clamp, if available, and unscrew the box nut counterclockwise, and take out
the hold-down ring, membrane and O-Ring. Then pour out the old electrolyte into a beaker for disposal.
CAUTION: Avoid contact of the electrolyte with skin, eyes and clothing. In case of contact wash
immediately - rubber gloves and safety glasses are recommended.
c. Clean the electrode with the alcohol wipes included in the electrolyte replacement kit. All oxidation residue
must be removed before re-assembly. When dirt is found inside the sensor assembly, wash the dirt off with
electrolyte.
d. Hold the sensor assembly with the sensing electrode up. Close the pressure compensation port with a tissue.
Pour approximately 10cc of fresh electrolyte from the wash bottle into the sensor and rinse the inside of the
sensor. Empty the electrolyte into the beaker.
e. Place the O-ring on top of the washer. Then transfer one drop of electrolyte from the plastic wash bottle to the
exposed electrode surface.
f. Place a new membrane into the hold-down ring and carefully place the plastic hold-down ring on top of the
sensor body with the ring ears in the slots of the sensor body. Then fasten the sensor cover over the
assembly.
CAUTION: Never touch the membrane with your hands. Use rubber gloves or tweezers.
g. Invert the sensor so that the membrane is down. If this is the first time that electrolyte has been replace, there
should be a round Mili-Seal covering the pressure compensation screw. This Mili-Seal prevented loss of
electrolyte during shipment. Remove and discard the round Mili-Seal and remove the screw to expose the
electrolyte supply port.
h. Transfer electrolyte from the plastic wash bottle into the electrolyte supply port until the level is at the
maximum level line on the side of the sensor body.
i. Replace the pressure compensation screw into the electrolyte supply port.
j. Replace the sensor housing cover.
k. Install the sensor assembly into the enclosure hub and tighten firmly.
l. Reconnect the sensor harness to the transmitter, carefully install the transmitter into the housing and restore
system power.
m. Recalibrate the transmitter following the instructions in Section 6 Calibration .
SMC 5100-XX-IT Toxic Gas Detector Module 63
US 14 Gas Sensor Module Calibration