Detcon FP-524D-HRT - Manual (Page 38)

Model FP-524D-HRT
FP-524D-HRT Instruction Manual Rev. 0.1 Page 34 of 48
4. Upon entering Auto Zero Calibration the procedure will prompt to begin Auto Zero Calibration. If zero
gas is to be applied to the sensor, apply the gas.
NOTE: Upon entering calibration the 4-20mA signal drops to 2mA and is held at this level
until the program returns to normal operation.
5. The procedure will prompt to verify that no gas is present, and the sensor will perform Auto Zero.
6. The sensor will scroll “Zero Cal . . . Setting Zero . . . Zero Saved” twice.
7. After successfully setting Zero Cal the sensor and the HART Interface will return to Automatic Mode.
8. Remove the zero gas and calibration adapter if applicable.
Auto Span
The Auto Span function is used to calibrate the sensor. Unless otherwise specified by the associated sensor
manual, span calibration is recommended at 50% of range.
Material Requirements:
 Handheld Communicator or PC and interface for HRT Bridge.
 Detcon PN 613-120000-000 Splash Guard with integral Cal Port -OR-
-Detcon PN 943-000006-132 Threaded Calibration Adapter
 Detcon PN 942-520124-050 50% LEL Methane in balance air (recommended) or other suitable span gas
containing a certified level of % LEL concentration of combustible gas in air balance. A flow fixed rate of
200-500cc/min is recommended.
NOTE: Refer to Section 3.4.2 AutoSpan for information regarding Span Gas, flow rates, cross
interference, or other sensor specific criteria.
Auto Span consists of entering “Autospan Cal” and following the display. The procedure will ask for the
application of span gas. The applied gas concentration must be equal to the Autospan gas level setting. The
factory default setting and recommendation for span gas concentration is normally 50% of range. If a span gas
containing the recommended concentration is not available, other concentrations may be used as long as they
fall between 5% and 100% of range. However, any alternate span gas concentration value must be set in the
“Auto Span Level” field before proceeding with “Autospan cal”.
CAUTION: Verification that the calibration gas level setting matches the calibration span gas
concentration is required before executing “Autospan Cal”. These two numbers must be equal. Refer
to the appropriate sensor manual for more information.
1. If applicable install the Calibration Adapter or Splash Guard Adapter with integral Cal Port.
2. Verify that the Auto Span Level is equal to the calibration span gas concentration. If the Auto Span Level
is not equal to the Calibration span gas concentration, adjust the Auto Span Level.
3. Connect the Cal Gas to the sensor, but do not apply the gas.
4. Select “Autospan Cal” from the Sensor Calibration section of the screen.
NOTE: Upon entering calibration the 4-20mA signal drops to 2mA and is held at this level
until the program returns to normal operation.
5. Upon entering the procedure the procedure will prompt to begin Auto Span Calibration.