ECD DO82, Instructional Manual

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4.2.2 STAND
ARDIZE
C
ALIBRATION
D
ESCRIPTION
A Standardize Calibration is a single point calibration where the transmitter’s reading is adjusted to agree with a solution
of known value, either a calibration standard, a grab sample, or a laboratory determined value. In many cases the
constituents, the pressure, and the temperature of process solution are very different from the calibration solution. In
these cases, once the sensor has equilibrated the Zero Point, or Offset value, may have shifted from the original
calibration point. Standardization allows for correction of this type of offset.
When the STAND key is pressed, the user is prompted to ENTER VALUE. The user enters the value they want the
transmitter to read and press OK. The user is then prompted to accept the value (YES/NO), and the calibration is
complete. Standardizations are single point calibrations.
At the end of each calibration the Offset and Slope are displayed in the respective units: pH, mV, ppm, or mg/l.
4.2.3 MANUAL C
ALIBRATION
D
ESCRIPTION
Manual calibration allows the user to enter calibration data for an electrode into the transmitter without performing a
calibration. A MANUAL Calibration requires the entry of three pieces of data: (1) A concentration with the (2)
corresponding mV and (3) a slope for the electrode. This allows laboratory generated calibration data for an electrode
to be entered in a remote analyzer where calibration is difficult or impractical.
Example: MANUAL Calibration for a pH electrode
1. Calibrate the pH electrode in the laboratory
2. Record the mV value of some pH Standard, pH 7.00 buffer = 6.8 mV (any pH
–
mV pair will work)
3. Calculate and Record the slope of the electrode, -58.2 mV/pH
4. Install the electrode into the field mounted sensor
5. Press MANUAL and enter the pH value, 7.00 pH, press mV, and enter the corresponding mV value, 6.8 mV,
press OK, Accept Offset?, press YES, enter slope -58.2 mV/pH, press OK, Accept Slope?, Press YES
6. The Calibration is complete, the Offset and Slope values are displayed, press OK to exit
4.2.4 CAL (C
ALIBRATION
M
ENU
)
Four options are available, AUTO , STAND , MANUAL , and TEMP .

AUTO is a two point calibration. The calibration proceeds in two steps, AutoCal 1 is an offset calibration and
AutoCal 2 is a slop calibration. Auto Cal provides automatic solution recognition of the calibration solutions used
for each measurement in accordance with the following list:
1. pH Calibration Buffers (US Standard), pH 4.01, pH 7.00, and pH 10.00 (see Appendix A)
2. ORP Calibration Solutions: Quinhydrone saturated: pH 7.00 = +89 mV, pH 4.01 = +266 mV
3. pIon Calibration Solutions: 1.00, 10.00, 100.00 ppb, ppm, ppt (thousand)
4. Dissolved Oxygen: Zero ppm (Sodium sulfite, Na2SO3 in water), Air saturated water, 8.25 ppm
Any two solutions can be used for AUTO calibration however if solutions other than those listed above are used
for calibration then the calibration values must be entered manually.

STAND is standardization, a single point calibration. Standardizations are typically used to adjust the process
reading to agree with a laboratory determined “grab sample” reading.

MANUAL
is a data entry screen. Manual calibration allows the user to enter a concentration with the
corresponding mV value, and a slope for an electrode. Laboratory generated calibration data for an electrode can
be input to a remote analyzer where calibration is difficult or impractical.

TEMP allows the displayed temperature to be trimmed to agree with actual process temperature.