Emerson Rosemount 1066, Инструкция по эксплуатации

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Instruction Manual Section 9: Calibration
LIQ-MAN-1066 April 2017
Calibration 69
Manual Calibration – pH
New sensors must be calibrated before use. Regular recalibration is
also necessary. Use manual calibration if non-standard buffers are
being used; otherwise, use auto calibration. Auto calibration avoids
common pitfalls and reduces errors. The adjacent appears after
selecting Manual pH calibration.
Entering a Known Slope Value – pH
If the electrode slope is known from other measurements, it can be
entered directly in the 1066 transmitter. The slope must be entered as
the slope at 25 °C.
Standardization – pH
The pH measured by the 1066 transmitter can be hanged to match the
reading from a second or referee instrument. The process of making
the two readings agree is called standardization. During
standardization, the difference between the two pH values is
converted to the equivalent voltage. The voltage, called the reference
offset, is added to all subsequent measured cell voltages before they are converted to pH. If a
standardized sensor is placed in a buffer solution, the measured pH will differ from the buffer pH
by an amount equivalent to the standardization offset.
This screen may appear if pH Cal is unsuccessful. An Offset Error will
generate this screen display:
If the pH Cal is successful, the screen will return to the Cal sub-menu.
SMART sensor auto calibration upload – pH
All calibration data including slope (mV/pH unit), offset (mV), glass impedance (MegOhms), and
reference impedance (kOhms) is automatically downloaded to the SMART sensor upon successful
calibration. This data transfer to the sensor is transparent and does not require any user action.
Calibrated SMART sensors will be loop-calibrated when wired or attached (via VP8 cable
connection) to any SMART-enabled Rosemount instrument.
To calibrate any SMART sensor, choose any available calibration method. Note that new SMART
sensors upon first shipment from Emerson are pre-calibrated and do not require buffer calibration
or standardization to be used in process immediately.
9.2.2
9.2.3
9.2.4
9.2.5
1.234 µS/cm 25.0 ºC
S
N
pH Manual Cal
Buffer 1
Buffer 2
1.234 µS/cm 25.0 ºC
S
N
Enter Value
07.00pH
1.234 µS/cm 25.0 ºC
S
N
pH Slope@25ºC
59.16 mV/pH
1.234 µS/cm 25.0 ºC
S
N
Standardize
Offset Error
Calculated: 96mV
Max: 60mV
Press EXIT