User Manual

ISA 200 RAL (O) ENMET Corporation
13
§ press the SELECT switch.
§ "ZERO = 30 .00V" is displayed. This is a timer that counts down from 30 seconds, at the end of that time the
procedure is finished. The instrument sets the clean air voltage point for the CO sensor and the 20.9% O
2
point for
the oxygen sensor if it is present. It then examines the validity of these values; if they are valid, it goes back to the
operational display. If a failure occurs, "Fault-01" is displayed in place of PPM reading in the operational display.
FAULT 01 indicates a clean air fault. Verify the proper zero gas is attached to the calibration Port and the sample-
calibrate valve is up toward the calibration port. Repeat automatic zeroing procedure. If fault 01 still occurs, replace
sensor in accordance with section 5.2.
After this procedure is complete, be sure to return the red handle of the Sample-Calibrate valve to the down position,
pointing toward the Sample Port. If the Sample-Calibrate valve is not switched back to the sample port, the low flow
fault indication is activated when the zero gas is removed.
5.1.3 Calibration
Insertion of a valid key results in the display: "run AUTOMATIC ZEROING". Press the OPTION switch once; "run
FULL CALIBRATION" is displayed. Press the SELECT switch; "ATTACH ZERO GAS" is displayed; this is the
start of the automatic zeroing procedure as described in paragraph 5.1.2, above. When this procedure is complete,
"ATTACH SPAN GAS - SPAN = 20" is displayed to indicate that the correct span gas for this procedure is 20 ppm
CO in a mixture of 20.9% oxygen in nitrogen. Do Not Use Any Other Than The Correct Span Gas For This
Procedure.
Pressing the OPTION switch at this point aborts the procedure and sets the display at the "exit MAINTENANCE
MODE" position.
From Automatic Zeroing
Example: Full Calibration Flow Chart
TO CONTINUE THE PROCEDURE:
§ Attach the correct span gas to the Calibration Port with the calibration adapter turn the red handle of the Sample-
Calibrate valve up toward the Calibration Port. See Figure 7.
§ Open the cylinder valve, set the regulator at 55 psig.
§ Allow the calibration gas to flow for at least one minute , then press the SELECT switch.
CAUTION: Pressure fluctuations may lead to aberrant oxygen readings if the SELECT switch is activated in less than
one minute.
§ "SPAN = 120 .00V" is displayed. This is a timer that counts down 120 seconds, at that point the procedure is
complete. The “.00V”portion of the display reflects the sensor signal, as it responds to the CO gas. This value
should increase.
After a valid zero and calibration, the instrument reverts to the operational display.
O
S
Invalid
Valid
O
S
S
S
ATTACH SPAN
GAS PPM CO
run FULL
CALIBRATION
ATTACH
ZERO GAS
SPAN=120 .65V
20.9 130 00.0
ZERO=30 .00V
20.9 130 00.0
Exit Maintenance Mode
Return to Operational Display
O
Exit Maintenance Mode
To Selectable Alarms
O = Option Switch
S = Select Switch
Return to Operational Display with
“Fault 01, Fault 02 or Fault 03”