Teledyne 2020 - Explosion proof thermal conductivity analyzer - Manual (Page 46)

4 Operation Model 2020
4-12 Teledyne Analytical Instruments
the curve. The user decides on the number of points, based on the precision
required.
The manual mode only requires entering the values for each correction
point into the microprocessor via the front panel buttons. Again, the number
of points required is determined by the user.
4.4 The Zero and Span Functions
(1) The Model 2020 can have as many as three analysis ranges plus a
special calibration range (Cal Range); and the analysis ranges, if more than
one, may be programmed for separate or identical gas applications.
(2) If all ranges are for the same application, then you will not need the
Cal Range. Calibrating any one of the ranges will automatically calibrate the
others.
(3) If: a) each range is programmed for a different gas application, b)
your sensor calibration has drifted less than 10 %, and c) your Cal Range
was calibrated along with your other ranges when last calibrated, then you
can use the Cal Range to calibrate all applications ranges at once.
If your Model 2020 analyzer fits the paragraph (3) description, above,
use the Cal Range. If your analyzer has drifted more than 10 %, calibrate
each range individually.
CAUTION: Always allow 4-5 hours warm-up time before cali-
brating, if your analyzer has been disconnected
from its power source. This does not apply if the
analyzer was plugged in but was in STANDBY.
The analyzer is calibrated using reference, zero, and span gases. Gas
requirements are covered in detail in chapter 3, section 3.4 Gas
Connections. Check that calibration gases are connected to the analyzer
according to the instructions in section 3.4, observing all the prescribed
precautions.
Note: Shut off the gas pressure before connecting it to the analyzer,
and be sure to limit pressure to 40 psig or less when turning it
back on.
Readjust the gas pressure into the analyzer until the flowrate through
the sensor settles between 50 to 200 cc/min (approximately 0.1 to 0.4 scfh).
Note: Always keep the zero calibration gases flow as close as the
flowrate of sample gas as possible