Hach-Lange ORBISPHERE Model 51x User Manual - Manual (Page 67)

65
Calibration menu
7.6 Interference calibration (TC sensor)
7.7 Barometric pressure calibration
7.8 External pressure calibration (optional sensor)
Interference calibration (TC sensor)
This calibration is available for TC sensors and is required when one of the interferences has been
enabled (see
Interferences configuration on page 55 ). The lower part of the screen displays the actual
measurement.
•
Select from the interfering gas to be calibrated from those available, or press the Change
configuration
button to reconfigure and go back to the process described in Interferences
configuration on page 55
• Hold during calibration : Selected by default, this holds the measurement sequence to avoid storing
invalid values during calibration.
Instructions For interfering oxygen on measured hydrogen or nitrogen, expose both
sensors to ambient air, or a 100% oxygen source, and press Start to initiate
the calibration.
For interfering hydrogen on measured oxygen or nitrogen, expose
both sensors to a 100% hydrogen source and press Start to initiate
the calibration.
Barometric pressure calibration
Upper box shows the barometric pressure measured by the instrument.
Using a precision certified barometer, measure barometric pressure in the location where the measuring
instrument is used. Compare the values, if values are the same press Cancel, otherwise enter the new
barometric value in the lower box and Validate the new setting.
On completion a calibration report is created.
Note:
The barometric sensor has been factory calibrated.
External pressure calibration
Two calibration methods for the external pressure sensor can be selected:
•
Two point calibration (recommended)
• One point calibration
By default the two point calibration is selected.
Two point calibration
(recommended) Connect a certified absolute pressure gauge to the sample line, and use a
certified precision barometer.
•
The two point calibration starts with barometric pressure for the lower
point. Expose the external pressure sensor to the atmosphere.
Enter the barometric pressure read on the barometer in the upper
window and validate P1.
• Expose the external pressure sensor to line pressure, making sure it is
exposed to the same pressure as the certified absolute pressure gauge.
Enter the absolute pressure value read on the certified absolute
pressure gauge in the lower box, and validate P2.
Note: Any pressure can be used for P1 and P2, but for an accurate
calibration P1 and P2 should be as different as possible.
One point calibration Connect a certified absolute pressure gauge to the sample line.
•
Expose the external pressure sensor to the line pressure, making sure it
is exposed to the same pressure as the certified absolute pressure
gauge.
Enter the absolute pressure value read on the certified absolute
pressure gauge in lower box, and validate P1.
Note: Any pressure can be used for P1, but for one point it should be as
close as possible to the sample pressure