Teledyne 311 - Portable trace oxygen analyzer - Manual (Page 9)

1) Stand the instrument upright on a level surface, and with the range switch in the
“OFF” position, check the alignment of the meter pointer with the zero mark on
the scale. Use the mirror to eliminate parallax, and adjust the screw on the face
of the meter, if necessary, until the pointer and zero mark are in precise coinci-
dence.
2) Advance the range switch to the “CAL” position.
3) Install the plastic tube equipped male disconnect fitting in either of the analyzer’s
sample ports, and a blank disconnect fitting in the other port (direction of sample
flow is of no importance). A pump is recommended on the plastic tube. Pump
the tube until the meter reading is stable.
CAUTION: DO NOT SUCK ON THE TUBE WITH YOUR MOUTH, THERE IS A
POSSIBILITY THE MICRO-FUEL CELL MAY LEAK. THE CELL CONTAINS KOH
SOLUTION WHICH IS CAUSTIC AND EXTREMELY HAZARDOUS!
4) Unlock and adjust the span control until the meter pointer is in coincidence with
the “CAL” mark on the meter scale. BE SURE TO RELOCK THE
CONTROL AFTER THE ADJUSTMENT IS MADE.
5) Immediately after Step 4 has been accomplished, disconnect the tubing equipped
calibration fitting, and plug in either the sample or a source of inert gas.
If the instrument is to be used for sampling after the calibration procedure has been completed,
follow the decreasing oxygen reading by positioning the range switch so that the meter gives the
best possible resolution of the oxygen. DO NOT ATTEMPT TO ACTUALLY TAKE A
READING UNTIL THE METER INDICATION STABILIZES. If the sample oxygen
content lies within the limits of the X1 range (0-10 ppm), an overnight purge is recommended for
the instrument to recover sufficiently from the effects of the 209,000 ppm oxygen concentration
of air (over four decades of range differential). Recovery time is proportionally less the coarser
ranges.
If, on the other hand, the instrument is not to be used immediately after calibration, and a low
ppm oxygen gas is being employed as a purge, allow the manifold to be purged overnight, and
then disconnect both male fittings. ALWAYS DISCONNECT THE SOURCE FITTING
FIRST, AND IMMEDIATELY THEREAFTER, THE VENT FITTING.
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