Hach DRB 200, Instrument Manual, Page: 22 / 32

22
Maintenance
1. Fill a clean, empty vial with glycerol at room temperature,
and insert the thermometer until it touches the bottom of the
vial.
2. When the thermometer is in the vial, the level of the glycerol
must be 51 mm ± 0.5 mm from the bottom.
3. Insert the vial in the center opening of the second row of the
test block.
4. Start the temperature program for 150 °C, 60 minutes (or the
COD program) for this block.
5. When the heating phase is complete, the thermometer
temperature should be the same as the temperature shown on
the display.
3.3 Changing the Protective Covers
1. Open the protective cover approximately 45°. Hold the
inside of the external hinge with your thumb.
2. Press your thumb against the inside of the cover. Carefully
lift each side of the cover out of its mounting.
3. Fit a new protective cover by following steps 1-2 in reverse
order.
Figure 5 Changing the Protective Covers