Operation LXT-220 DO
Teledyne Analytical Instruments 46
Buffer
Setup
Status
Parameter Selection Menu
1DO .00 ppm
Cal .0 mV
Standardization menu pH
• BUFFER: Perform a 1 or a 2 point calibration
• SETUP: Set up the range of the 4-20 mA output
• STATUS: Information only. Shows the data stored from the last
calibration.
3.4.2.1 BUFFER MENU
From the parameter selecti on menu chose the top line ( the
BUFFER command) and pres s the two horizontal ◄► CALIBRATE
keys simultaneously to ent er the BUFFER calibration sub menu. Both
the one-point calibration (standardize) and the two-poi nt (span)
calibrations are availab le within this menu. The proce dures for each
calibration function are given below.
3.4.2.2 ONE-POINT BUFFER CALIBRATION (STANDARDIZE)
Because all dissolved oxygen electrodes experience minor
variations, buffer calibrations are necessary before installing the
electrodes in service. Also, occasional calibrations are necessary to
compensate for electrode degradation while in service. For
measurement specifics refer to the dissolved oxygen sensor manual.
Procedure:
1. Be sure that the cursor is located under the "1" as illustrated.
2. For diagnostic reasons note the ppm and mV values from the
prior calibration.