Gow-Mac 75-850-BV, Operating Manual

Page: 6 / 14

GOW-MAC Instrument Co.
6
Push the Advance Key to display [
.9nr
] in the upper display and the message
source (such as [
L.hi
]) in the lower display.
Use the Up and Down keys to scroll through possible responses, such as Clear
[
CLr
] or Silence [
S.L
]. Then push the Advance or Infinity key to execute the action.
Er. 1
-
Error Input 1:
The sensor input generated a value lower than the allowable
signal range. Enter a valid input.
100
- Device Error: Controller displays internal malfunction message at Power
Up.
i. Set Point
a. To set the set point: turn the unit “on” and then push the Up or Down arrow to
adjust to the desired operating temperature.
5. Hydrogen Breakthrough
The H
2
Separator is equipped with a palladium/silver alloy membrane. Its function is to
quantitatively remove the hydrogen balance gas from a hydrogen sample leaving only
the impurities in the helium carrier gas stream. After using the system for a period of
time with hydrogen, the appearance of a hydrogen peak will be seen. This is caused
by the buildup of carbonaceous deposits inside the palladium tube. By allowing air to
pass through the tube at operating temperature it is possible to remove this buildup and
restore the Separator to its original state.
1. Turn the BYPASS VALVE to "Bypass/Recondition" position.
2. Set the AIR flow rate to the optimum flow setting as directed by the chromatogram
located at the back of this manual. Set temperature to 450 °C for 1 hour. This burns
off any deposits on the palladium/silver alloy membrane.
3. Turn BYPASS VALVE to the "Series/Run" position to connect the Separator to the
GC. Purge for 15 minutes.
IT IS IMPORTANT THAT THE AIR SUPPLY USED FOR
THIS INSTRUMENT BE AT LEAST ZERO GRADE
(CONTAINING < 1PPM OF HYDROCARBONS). IMPURE
AIR CAN HELP TO CAUSE THE SEPARATOR TO NEED
RECONDITIONING MORE FREQUENTLY. ALSO
HALOGENS, ORGANOMETALS, SULFUR COMPOUNDS,
DOPING GASES AND OTHER HEAVY METALS CAN CAUSE
PLUGGING OF THE SEPARATOR TUBE AND REQUIRE
TUBE REPLACEMENT.