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2020 Software Manual
Calibration
Periodic calibration is required to compensate for 2020 output
changes due to inlet filter restriction, ionization chamber cleanliness,
pump wear and other factors.
During calibration, 2020 is first exposed to zero air. A small signal is
generated. This zero signal is stored by the microprocessor.
2020 is next exposed to span gas. This span gas signal is stored by
the microprocessor. The microprocessor subtracts the zero signal
from the span gas signal and divides the difference by the user-
entered span gas concentration. The resulting sensitivity is stored in
the selected Cal Memory with the zero signal and the alarm levels.
This number is then multiplied by the response factor and displayed.
2020 readings are always relative to the calibration gas. After
calibration with isobutylene, 2020 will respond directly in units
equivalent to isobutylene. Most volatile organic compounds will be
detected by 2020. It cannot distinguish between isobutylene and
other ionizable compounds. A reading of 10 ppm indicates all
ionizable compounds that are present have generated an ion current
proportional to 10 ppm of isobutylene. The reading is actually 10
ppm isobutylene equivale nt units. 2020 readings give an indication of
the total ionizables present and their concentration relative to the
calibration gas.
Datalogger
Interval Operation
The microprocessor accumulates all readings in an averaging
interval, that you select, and determines the minimum, average and
maximum readings. It stores these numbers along with the highest
priority instrument status and the most recent time and date. The
datalogger can store 1000 of these entries.
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Troubleshooting
