Xylem DH-21 - Manual (Page 17)

DH-21
Installation 2-5
Figure 2-3
Accessing the Battery Pack and Desiccant
Desiccant Cartridge can be reused by drying them in an oven at 160 F to 180 F for 24 hours or
until the desiccant returns to a dark blue color.
Features of the Well Head Assembly:
(1) Desiccant Cartridge
(2) Circuit Board/Dry Air Assembly
(3) Desiccant Packs
(4) Battery Pack
To inspect the Desiccant Cartridge (1), gently pull the Circuit Board/Dry Air Assembly (2) in the
direction shown on the label, away from the lower portion of the well head assembly. Remove
the Desiccant Cartridge from the rubber plug (do not remove the rubber plug).
When reassembling, firmly press the rubber plug into place before inserting the Desiccant
Cartridge. Then gently push the Circuit Board/Dry Air Assembly back into the lower portion of
the Well Head Assembly.
2.4 Range of Stage
Use the following chart to determine the maximum depth at which your “W ATER LOG” will
measure pressure accurately. Do not place your “W ATER LOG” at more than twice the rated
depth for your model's range, or the instrument will be damaged.
Model Pressure Range Depth Range Accuracy 0.05% 0.03%
DH21-05 zero to 05 psi zero to 11.53 ft. +0.006 ft. +0.003*
DH21-15 zero to 15 psi zero to 34.60 ft. +0.017 ft +0.010
DH21-30 zero to 30 psi zero to 69.20 ft. +0.035 ft. +0.021
NOTE: Depth calculations are derived from the standard equation that one psi is generated by a
column of water 27.680 inches deep at 39.4 F.