Instruction manual

MODEL XMT-A-FF/FI SECTION 9.0

CALIBRATION — DISSOLVED OXYGEN

4. Press MENU. The main menu screen appears. Choose Calibrate.

5. Choose Oxygen.

6. Choose InProcess.

7. The screen at left appears for two seconds.

8. The screen at left appears. The number in the first line is the concentra-

tion of dissolved oxygen based on the previous calibration. Wait until the

reading is stable, then press ENTER.

9. The screen at left appears. Press ENTER. The transmitter will store the

present sensor current and temperature and use those values in the cal-

ibration.

10. Use the arrow keys to change the value in the second line to match the

reading of the standard instrument. To return to the main display press

MENU then EXIT.

11. This screen appears momentarily if the sensitivity (sensor current divid-

ed by concentration) is much higher or lower than expected. The display

then returns to the screen in step 5. See Section 15 for troubleshooting.

9.4 PROCEDURE - CALIBRATING THE SENSOR AGAINST A STANDARD INSTRUMENT

The sensor can be calibrated against a standard instrument. For oxygen sensors installed in aeration basins in

waste treatment plants, calibration against a second instrument is often preferred. For an accurate calibration be

sure that . . .

1. The standard instrument has been zeroed and calibrated against water-saturated air following the manufac-

turer's instructions.

2. The standard sensor is immersed in the liquid as close to the process sensor as possible.

3. Adequate time is allowed for the standard sensor to stabilize before calibrating the process instrument.

Cal? AirCal

InProcess

Zero

Wait for

Stable reading.

Calibrate

Sim. PV

Program Display

Stable? 10.00ppm

Press enter.

Take sample;

Press enter.

Sample 10.00ppm

Cal 1

0.00ppm

Calibration

Error

Cal?

Oxygen

Temp