LTH Electronics MTD75, Operation Manual

Page: 135 / 266

pH Calibration
MTD75 Operation Guide - 133 -
pH Cali
bration
Auto pH Sensor Calibration
The Auto pH sensor calibration is a two point offset and slope calibration, which requires the use of a 4
and 9 pH buffer solutions. These are nominal values from which the instrument converts to exact
buffer values due to temperature variations. To accomplish this, the instrument uses a buffer table
which comes pre-configured with the following two LTH buffers:
4pH – LTH Order Number 138/199
9pH – LTH Order Number 138/201
If the user wishes to use alternative buffers then they must enter in their own buffer values at different
temperatures by following the custom buffer instructions on page 132.
In order for the auto calibration to work correctly, the buffer temperature must either be measured by
the instrument during calibration, or if manual temperature compensation is being used the buffer
temperature must be entered in the “Calibration Manual Temperature Input” in the calibration menu.
Calibration Principle
To use Auto calibration first set the calibration
principle to Auto.

/

– Select Option
EXIT – Cancel
– Save Selection
pH Auto Calibration
To start the pH calibration, select the “pH Calibration”
item from the desired channel’s calibration menu.
– Enter pH Auto Calibration