Sampling System Checks; Summary Of Preliminary Checks; Loss Of Zero Control - Teledyne 212R Instruction Manual

Thermal Conductivity Analyzer
Check to see that both the analyzer and recorder are being furnished
electrical power. Check to see that the analyzer and recorder fuses are intact.
Check all electrical connections outside of the analyzer.
6.1.2
Be sure that there is an adequate supply of reference gas and that the
sample and reference path flowrates are correct. Check to see that there are
no obstructions in the vent paths from the analyzer. Check all external
plumbing connections for leaks with soap water.
6.1.3
The analyzer inner door should not be opened and no adjustments, beyond
manipulation of the normally used controls, should be made until all the afore-
mentioned preliminaries have been completed and any necessary remedial
repairs effected.
6.2
If loss of zero control on Range #1 is experienced during initial startup or
after the reference gas supply has been changed, the dynamic balance procedure
must be repeated.
Loss of zero control, under such circumstances, indicates that the impurity
concentration within the reference gas is different than that of the gas used during
factory checkout (or the previous cylinder) and does not in itself indicate a
defective analyzer.
The analyzer was adjusted at the factory to have a zero balance at close to
the midpoint of the zero control potentiometer (dual dial reading of 500) with a
common source of high purity cylinder gas supplying both the sample and
reference paths of the cell. If the recorder is off scale and cannot be returned
with the zero control, the dynamic balance procedure must be employed to
restore control before further conclusions as to instrument performance can be
made.
18

Sampling System Checks.

Summary of Preliminary Checks.

Loss of Zero Control.

Teledyne Analytical Instruments
Model 212R