YSI 52 - Manual (Page 10)

Calibration Section 3
3.3 CALIBRATION IN AIR
Three separate calibration techniques are discussed here: calibration in air, calibration in
air-saturated water, and calibration by Winkler titration. Choose the one technique which
best fits your application. Calibration in air is the simplest and most accurate method of
calibration.
To calibrate in air:
1. Place a prepared probe in air at 100% relative humidity. To achieve this, BOD probes
can be placed in a BOD bottle with approximately 1” of water. Field probes can be
placed in the plastic calibration bottle with a moistened sponge, or calibrated with the
5075A Calibration Chamber.
2. Switch to CALIBRATE. The display will read:
C a l i b r a t e
i n p e r c e n t ?
Select percent calibration by pressing CONFIRM. A display similar to the one below
will be shown.
E n t e r c a l v a l u e
L a s t = 9 6. 4 %
3. Using ¿ and À, adjust the number to the calibration value determined from the
altitude or pressure chart on the back of the Model 52. SKIP sets the value to 100.0%;
and shows the following display:
E n t e r c a l v a l u e
S a t . = 1 0 0 %
you may wish to do this to bring the setting quickly to a value near the one you want,
then continue with ¿ and À. Pressing SKIP again sets the value to 0.0% (see Zeroing
the Probe). Pressing SKIP a third time brings it back to the last calibration value.
YSI, Incorporated Model 52 6