Instruction Manual
Ammonia Gas-sensing Electrode
17
high temperatures
membrane failure
replace membrane
(wet, perforation,
discoloration)
samples and standards
allow samples and standards to come
standards not at
to room temperature before use
constant temperature
heat generated by
place insulating material between
magnetic stirrer
stirrer and beaker
defective inner body
refer to
Checking the Electrode
Inner Body
electrode exposed
hold electrode by outer body and
to air for extended period
pull on electrode cable. Internal
filling solution will flow under
membrane and restore electrode
response
Low Slope or
standards contaminated
prepare fresh standards
No Slope or incorrectly made
buffer not used
use recommended buffer
standard used as buffer
use buffer
electrode exposed
hold electrode by outer body and
to air for extended period
pull on electrode cable. internal
filling solution will flow under
membrane
and
restore
electrode
response
membrane failure
replace membrane
(wet, perforation,
discoloration)
defective inner body
refer to
Checking the Electrode
Inner Body
"Incorrect Answer"
incorrect scaling
plot millivolts on the linear axis. On
(but calibration of semi-log paper
the log axis, be sure concentration
curve is good)
numbers within each decade are
increasing with increasing
concentration
incorrect sign
be sure to note sign of millivolt
