Bird Technologies 4331 - Manual (Page 54)

Operation
The basic operations and maintenance procedures for the Model 4431 are
the same as those of the Model 43 as described in this instruction book.
Maintenance
The maintenance procedures for this model are essentially the same as for
the Model 43 except for the inclusion of the variable probe equipment. It is
not recommended that user make repairs on the probe assembly. If the
sampler malfunctions, we suggest the unit be returned to the factory. If for
a particular urgency, the user wants to make field replacement of the probe
assembly themselves, proceed as follows:
1. To reach the probe, remove the four 8-32 x 3/8 inch Phil-
lips flat head screws on the sides of the case near the
back.
2. Grasp the back cover firmly, by the tabs behind the line
connectors, and pull straight backward to remove the
back cover.
3. Use a 1/16 hex socket Hex wrench to loosen and remove
the small coupling control knob on the front of the watt-
meter, just above the Plug-In Element socket.
4. Remove the two 8-32 x 1/4 inch pan head screws fasten-
ing the guide and movable plate assembly to the back of
the line section.
5. Restore the control knob to the front of the shaft tempo-
rarily, then rotate the shaft counterclockwise until the
threaded collar is free of the screw shaft and pull the
movable probe plate straight out of the pin and guide
bushing.
6. Unscrew the 5/8 hex instrument nut on the BNC connec-
tor (outside) and pull the sampler connector inside the
case. The probe plate assembly, P/N 4431-003, is now re-
leased and may be replaced in its entirety.
Bird Model 43 Wattmeter
40