Checking The Co Concentration; Fig. 25 Co 2 Equalization - Kendro HERAcell 240 Operating Instructions Manual

®
HERAcell 240 CO Incubator Operating Instructions
2
11. Maintenance
11.5 Checking the CO
To determine the precise value being measured by
the internal CO sensor, a comparative CO
2
rement should be performed quarterly.
If the result indicates a measured value deviation of
> 0.5 % CO , a CO equalization should be performed.
2 2
For this, the unit's CO
2
measured value obtained in the comparative measu-
rement.
A calibrated instrument offering an accuracy of
≤ ± 0.3 % CO
should be employed for the compari-
2
son. A suitable Infrared (IR) meter is available from
Kendro:
•
Portable IR meter. (Refer to Chapter 12, "Spare
Parts and Accessories" for the order number.)
The sample is taken via the measurement opening in
the glass door. The comparative measurement must
be made when the unit temperature has stabilized.
Performing a Comparative Measurement:
1. Switch the unit on at the main power switch.
2. Define the CO setpoint, then wait until the unit
2
temperature has stabilized. The humidity must
build up. This may take several hours.
3. Insert the IR meter's probe through the measure-
ment opening [1] and into the sample chamber.
Wait until the instrument CO
4. Remove the probe, close the measurement
opening, and close the doors.
5. Calibrate the CO regulator accordingly. Refer to
2
the steps in Table 11.6.
Measurement Example:
•
CO setpoint: 5 %
2
•
Sample measurement: 5.6 %
NOTE – 6-port gas diaphragm models:
On units equipped with the optional 6-port gas
diaphragm, the measurement opening [2] is located in
one of the middle glass doors.
Version: 03.2001 / 50065640
Concentration
2
measu-
2
regulation is adjusted to the
reading is constant.
2
Figure 25
Fig. 25, CO equalization
2
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