Emerson Rosemount 1056, Instruction Manual

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The following screen will appear if the auto cal is
successful. The screen will return to the pH Buffer Cal
Menu.
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N pH Auto Cal
Slope: 59.16 mV/pH
Offset: 60 mV
1. A High Slope Error will generate this screen display:
2. A Low Slope Error will generate this screen display:
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N pH Auto Cal
High Slope Error
Calculated: 62.11 mV/pH
Max: 62.00 mV/pH
Press EXIT
3. An Offset Error will generate this screen display:
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N pH Auto Cal
Low Slope Error
Calculated: 39.11mV/pH
Min: 40.00 mV/pH
Press EXIT
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N pH Auto Cal
Offset Error
Calculated: 61.22mV
Max: 60.00mV
Press EXIT
7.2.3 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 calibra-
tion.
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N pH Manual Cal
Buffer 1
Buffer 2
7.2.5 Standardization — pH
The pH measured by the Model 1056 analyzer can be
changed 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.
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N Enter Value
07.00pH
7.2.4 Entering A Known Slope Value — pH
If the electrode slope is known from other measure-
ments, it can be entered directly in the Model 1056 ana-
lyzer. The slope must be entered as the slope at 25°C.
S1: 1.234µS/cm 25.0ºC
S2: 12.34pH 25.0ºC
S N pH Slope@25ºC
59.16 mV/pH
The following screens may appear if the auto cal is unsuccessful.
Instruction Manual
LIQ-MAN-1056
Section 7.0: Calibration
April 2017