Environmental Express AutoBlock II - Manual (Page 22)

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the laboratory and when new methods are developed. It is also performed as
part of routine maintenance.
Sample Temperature
1. To perform temperature calibration, allow the AutoBlock to heat until
Graphite temperature stabilizes within one degree of Set Point
temperature.
2. Measure Sample temperature with a NIST traceable thermometer by
taking Sample temperature measurements from 8 variously located
samples, then average. The resulting number is your actual Sample
temperature.
Note: Use extreme caution if a mercury-containing thermometer is used.
A broken thermometer may cause permanent and irreversible
contamination to the AutoBlock.
3. Based on the difference (if any) between the current actual Sample
temperature and your desired Sample temperature, adjust the Set Point
temp accordingly.
4. When Graphite temp reaches the new, adjusted Set Point temp, re-measure
Sample temp, and then re-adjust Set Point temp as needed.
5. Continue this four-step process until an acceptable Sample temperature is
achieved.
5.4
Exhaust Fan
The Exhaust Fan box is located in the lower left portion of the screen. Pressing
On turn the fan on, and Off turns the fan off.
When Graphite temp reaches 40°C in the manual mode, the Exhaust Fan
automatically turns On as a safety precaution.
Once the fan is On, whether started manually or automatically, it will not end
operation until
(1) the graphite temp cools below 40°C, and
(2) the analyst manually presses the Off button.
In the event that noxious fumes or vapors are present and the exhaust fan is Off,
turn the exhaust fan On. See Service Mode (options section) for fan speed during
digestion procedures.