Detcon P-1000 - Manual (Page 18)

P-1000
Portable Model 1000 H2S Analyzer Rev. 1.0 Page 14 of 24
4.0 Calibration
4.1 Calibration Procedure – Zero
Material Requirements
™
Zero Air or N
2
gas cylinder
a) Connect zero air or N
2
gas to the “Span/Zero Gas Inlet Port” and switch the 3-way valve to the “Calibrate”
position. Apply zero air or N
2
gas at a rate of 500cc/min for 5 minutes prior to continuing.
b) Enter the calibration menu by holding the programming magnet stationary over “PGM 1” for 3 seconds
until the display reads “1-Zero Cal 2-Span Cal”, withdraw the magnet.
c) Enter the Zero Cal menu by holding the magnet stationary over “PGM 1” for 3 seconds until the display
reads: “Auto Zero”, and withdraw the magnet. The sensor will enter the Auto Zero mode, which lasts for
7 seconds. When complete, the display will read “Zero Complete” for 2 seconds and will report the date
of the last span as a reminder. The display will read; “Return to Normal Operation” for 3 seconds.
d) Turn off and remove the zero air or N
2
gas, and remove the gas from the unit. Auto zero is complete.
NOTE1: If the circuitry is unable to adjust the zero to the proper setting the sensor will enter a
calibration fault mode which will cause the display to alternate between the sensor’s current
status reading and the calibration fault screen which appears as: “Zero Cal Fault”.
NOTE2: Upon entering the calibration menu, the 4-20mA signal drops to 3.5 mA until the
unit returns to normal operation.
NOTE3: When a “Zero Cal Fault” occurs, the sensor microprocessor retains its previous zero
calibration reference.
4.2 Calibration Procedure - Span
It is advised that a Zero Calibration is performed prior to a Span Calibration.
Material Requirements
™ Detcon PN 943-003270-000 Programming Magnet
™ Span gas containing H
2
S gas in air or nitrogen. The target gas concentration is recommended at 50% of
range (which is the factory default) at a controlled flow rate of 500cc/min. Example: for a Model DM-
200-H
2
S sensor with a range of 0-100ppm, a test gas of 50ppm is recommended. For a sensor with a range
of 0-20ppm a test gas of 10ppm is recommended, etc. Other concentrations can be used as long as they
fall within 10% to 90% of range. See below for details.
CAUTION: Verification of the correct calibration gas level setting and calibration span gas
concentration is required before “span” calibration. These two numbers must be equal before
proceeding.
Calibration consists of entering the calibration function and following the menu-displayed instructions. The
display will ask for the application of span gas in a specific concentration. This concentration is equal to the
span gas level setting. The factory setting for span gas concentration is typically 50% of range, but may be
different depending on gas availability. For optional calibration, a span gas containing a concentration equal
to 50% of range is required. If a span gas containing 50% of range is not available, other concentrations may
be used as long as they fall within 10% to 90% of range. However, any alternate span gas concentration value