Hach 1720E User Manual page 28

Maintenance
Figure 7 Lamp Replacement
1. Lamp Housing
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3. After the bulb has cooled, remove as follows:
a. Wear cotton gloves to protect your hands and to avoid fingerprints on the bulb.
b. Grasp the bulb.
c. Twist the bulb in a counterclockwise direction, pulling out slightly, until it is
released from the housing.
d. Pull the lamp leads and connector through the hole in the lamp housing.
Do not touch the new bulb with bare hands. Etched glass and reduced lamp life will result.
Wear cotton gloves or grasp the lamp assembly with a tissue to avoid contamination. If
contamination occurs, clean the glass bulb portion with isopropyl alcohol.
Replace the bulb by reversing the above instructions. The bulb base only fits one way;
align the notch in the metal bulb flange with the hole in the lamp holder.
1
2. Lamp Assembly
2
3
3. Photo Detector