Hach-Lange HQD - BOD LDO Probe LBOD - Manual (Page 4)

4 DOC272.53.80025
Zero point calibration
Zero point calibration notes:
• The zero point calibration is only necessary for dissolved oxygen measurements
below 1 mg/L.
• The cobalt chloride acts as a reaction catalyst.
• It may take up to 30 minutes for a 0 mg/L point to be observed. A negative dissolved
oxygen concentration value indicates that a 0 mg/L has not yet been met.
• The calibration record is stored in the probe and the data log. The calibration is also
sent to a PC, printer, or flash memory stick if connected.
6. Put the LBOD
probe in the BOD
bottle and allow
approximately ten
minutes to
equilibrate.
7. Select
Calibrate then
Read. The display
will show
Stabilizing... and a
progress bar as the
probe stabilizes in
the standard.
8. The display
highlights the
standard value.
Continue with
Zero
point calibration if
desired. If not,
select Done to view
the calibration
summary.
9. Select Store to
accept the
calibration and
return to the
measurment mode.
The calibration
record is stored in
the probe and the
data log.
1. Fill a BOD bottle
full with deionized
water.
2. Add 300 mg of
sodium sulfite to the
bottle.
3. Add 2 mL of
cobalt chloride
solution.
4. Place the
stopper in the BOD
bottle and invert
several times to mix
the chemicals.
5. Place the LBOD
probe in the bottle
and start the stirrer.