Teledyne 326, 327 and 328 - Oxygen analyzers - Manual (Page 31)

Teledyne Analytical Instruments
Operations Operations Operations Operations Operations Model 326/327/328 Model 326/327/328 Model 326/327/328 Model 326/327/328 Model 326/327/328
4-3
4.5 Initial Calibration and Equilibration 4.5 Initial Calibration and Equilibration 4.5 Initial Calibration and Equilibration 4.5 Initial Calibration and Equilibration 4.5 Initial Calibration and Equilibration
Before stable operation can be guaranteed, the Micro-Fuel Cell will
require a period of time to adjust itself to its new environment. Monitoring
the integral meter, this period of time appears to be about 15 minutes. Actu-
ally, there will be a few percentage points of drift for a period of hours after
the first 15 minutes of stabilization. This can be demonstrated by recording
the output on a circular chart recorder for the first 24 hours of operation.
The instrument can be placed in service before it is completely stabilized.
Once it appears to have stabilized (usually about 15 minutes), the slight
instability during the first hours of operation is tolerable. The drift during
this period can easily be compensated by rezeroing before each reading.
If, on the other hand, reliable analysis, free of instrument distortion, is
required from the very onset of operation. TBE recommends a 24 hour run-
in period before operational calibration and service.
In either case, employ the following procedure:
1) Turn the analyzer range switch to the 0-25% (or highest range)
position. This establishes power to all components of the analyzer
at minimum sensitivity. If applicable, turn on the accessory
readout device.
2) Connect analyzer input to a supply of span gas or air.
Note: Note: Note: Note: Note: When practical, the instrument may be calibrated by withdrawing the When practical, the instrument may be calibrated by withdrawing the When practical, the instrument may be calibrated by withdrawing the When practical, the instrument may be calibrated by withdrawing the When practical, the instrument may be calibrated by withdrawing the
cell probe from the holder and exposing the cell to the surrounding
cell probe from the holder and exposing the cell to the surrounding cell probe from the holder and exposing the cell to the surrounding cell probe from the holder and exposing the cell to the surrounding cell probe from the holder and exposing the cell to the surrounding
atmosphere.
atmosphere. atmosphere. atmosphere. atmosphere.
3) Adjust the throttle valve so that an indicated flowrate of 2.0
SCFH (1000 ml/min) registers on the flowmeter. Wait about
three to five minutes (allow reading to stabilize) before
proceeding to next step.
4) Unlock and adjust the span control potentiometer until the meter
pointer is in coincidence with the CAL mark (black mark on the
red 0-25% scale, at 20.9%) on the meter scale. Relock the span
potentiometer.
Note: Note: Note: Note: Note: If the instrument does not have a 0-25% range, or if the surrounding If the instrument does not have a 0-25% range, or if the surrounding If the instrument does not have a 0-25% range, or if the surrounding If the instrument does not have a 0-25% range, or if the surrounding If the instrument does not have a 0-25% range, or if the surrounding
atmosphere cannot be used as a span gas, then a span gas will be
atmosphere cannot be used as a span gas, then a span gas will be atmosphere cannot be used as a span gas, then a span gas will be atmosphere cannot be used as a span gas, then a span gas will be atmosphere cannot be used as a span gas, then a span gas will be
needed. In that case, adjust the span control until the meter reads the
needed. In that case, adjust the span control until the meter reads the needed. In that case, adjust the span control until the meter reads the needed. In that case, adjust the span control until the meter reads the needed. In that case, adjust the span control until the meter reads the
concentration of the span gas.
concentration of the span gas. concentration of the span gas. concentration of the span gas. concentration of the span gas.
Note: Note: Note: Note: Note: If recorder or remote indicator is used for primary readout, calibrate to If recorder or remote indicator is used for primary readout, calibrate to If recorder or remote indicator is used for primary readout, calibrate to If recorder or remote indicator is used for primary readout, calibrate to If recorder or remote indicator is used for primary readout, calibrate to
83.9% of full scale on recorder or indicator for maximum accuracy.
83.9% of full scale on recorder or indicator for maximum accuracy. 83.9% of full scale on recorder or indicator for maximum accuracy. 83.9% of full scale on recorder or indicator for maximum accuracy. 83.9% of full scale on recorder or indicator for maximum accuracy.