Emerson 1057 Instruction Manual page 52

MODEL 1057
7.4.2 ENTERING THE CELL CONSTANT
New conductivity sensors rarely need calibration. The
cell constant printed on the label is sufficiently accurate
for most applications.
entered:
• When the unit is installed for the first time
• When the probe is replaced
The display screen for entering a cell Constant for the
sensor is shown. The default value is displayed in bold
type.
7.4.3 ZEROING THE INSTRUMENT
This procedure is used to compensate for small offsets
to the conductivity signal that are present even when
there is no conductivity to be measured. This procedure
is affected by the length of extension cable and should
always be repeated if any changes in extension cable or
sensor have been made. Electrically connect the
conductivity probe as it will actually be used and
place the measuring portion of the probe in air. Be
sure the probe is dry.
The adjacent screen will appear after selecting Zero
Cal from the Conductivity Calibration screen:
The adjacent screen will appear if zero Cal is successful.
The screen will return to the conductivity Cal Menu.
The adjacent screen may appear if zero Cal is unsuccessful.
7.4.4 CALIBRATING THE SENSOR IN A CONDUCTIVITY
STANDARD (IN PROCESS CAL)
This procedure is used to calibrate the sensor and
analyzer against a solution of known conductivity.
This is done by submerging the probe in the sample of
known conductivity, then adjusting the displayed value, if
necessary, to correspond to the conductivity value of
the sample. Turn temperature correction off and use the
conductivity of the standard. Use a calibrated ther-
mometer to measure temperature. The probe must be
cleaned before performing this procedure.
The adjacent screen will appear after selecting In
Process Cal from the Conductivity Calibration screen:
44
The cell constant should be
S1: 1.234µS/cm 1.234ºC
S2: 12.34pH 1.234ºC
S3: 12.34µS/cm 1.234ºC
SN Cell Constant
1.00000 /cm
S1: 1.234µS/cm 1.234ºC
S2: 12.34pH 1.234ºC
S3: 12.34µS/cm
SN Zero Cal
1.234ºC
In Air
In Water
S1: 1.234µS/cm 1.234ºC
S2: 12.34pH 1.234ºC
S3: 12.34µS/cm 1.234ºC
SN Zero Cal
Sensor Zero Done
S1: 1.234µS/cm 1.234ºC
S2: 12.34pH 1.234ºC
S3: 12.34µS/cm 1.234ºC
SN Zero Cal
Sensor Zero Fail
Offset too high
Press EXIT
S1: 1.234µS/cm 1.234ºC
S2: 12.34pH 1.234ºC
S3: 12.34µS/cm 1.234ºC
SN InProcess Cal
Wait for stable
reading.
SECTION 7.0
CALIBRATION