Calibration; Auto Calibration Description; Standardize Calibration Description; Manual Calibration Description - ECD TC80 Instruction Manual

4.0 CALIBRATION

The Model T80 transmitter provides three methods of calibration:
4.0.1 AUTO C
ALIBRATION DESCRIPTION
Auto calibration is the primary calibration method for all measurements. AUTO
calibration automatically recognizes the calibration solution the sensor is in and
proposes the actual temperature compensated value for acceptance. AUTO
calibration can be a single point or two point calibration. A single point calibration
sets the zero point or offset value of the sensor. The second calibration sets the slope
or span of the sensor.
When the AUTO key is pressed and Cal 1 or Cal2 is selected the transmitter displays
the PV (Process Variable) and the associated mV signal from the sensor. When the
reading has stabilized a calibration value is Automatically proposed, i.e. 7.00 pH, 0.00
ppm Chlorine. The user is prompted to accept the proposed calibration value or enter and accept another
value. Once Cal 1 is accepted the user is ask to continue to Cal 2, yes/no. If yes, the sensor is moved to the
second calibration solution and a second calibration value is proposed when the sensor has stabilized. Accept
the value and the calibration is complete.
At the end of each calibration the Offset and Slope are displayed in the respective units, pH, mV, ppm, Press OK
to save the calibration and write it to the sensor's memory.
4.0.2 STAND C
ARDIZE ALIBRATION DESCRIPTION
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 laboratory determined value. In many cases the constituents and the
pressure and temperature of the process solution are very different from the
calibration solution. In these cases, once the sensor has equilibrated to the process
environment, the Zero Point or Offset value may have shifted from the original
calibration point. Standardization allows for correction of this type of offset. It
changes the Offset value in a pH calibration. It changes the Slope value in a Chlorine
calibration. It is the primary calibration for Chlorine Sensors. Enter the Chlorine
value determined by a DPD test on the process water.
When the STAND key is pressed, the user is prompted to ENTER VALUE. The user enters the pH or Chlorine 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 or ppm, Press
OK to save the calibration and write it to the sensor's memory.
4.0.3 MANUAL C
ALIBRATION DESCRIPTION
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
Page 31 Model TC80