Thermo Fisher Scientific Ion Selective Electrodes Ammonia - Manual (Page 21)

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