Bird Technologies 4308 - Manual (Page 27)

Line Section or Element Coupling Circuit
If a problem should occur in the line section or element coupling circuit, it is advised
that the unit be returned to Bird Electronic Corporation for repair and recalibration.
Meter Housing
For access to the inside of the meter housing, the back cover must be taken off. To do
this:
1. Remove the four screws located near the back at the top and bot-
tom of the sides.
2. Pull the cover straight off.
Line Section and Circuit Board
1. Loosen the nuts on the meter terminals using a 5/16 inch wrench.
2. Remove the connecting wires on the meter terminals.
3. Remove the range switch knob. Use a 1/16 inch hex wrench to
loosen the set screw.
4 . Remove the two 10-32 Phillips head screws located on the front
of the meter housing on either side of the detector element. Sup-
port the line section while removing the 10-32 screws. The line
section with the attached circuit board will fall straight out the
back.
5. Detach the circuit board by removing the two screws that secure it
to the line section.
Be careful not to distort the spring finger of the dc contact that protrudes into the line
section. Also be careful not to lose either; the Teflon insulator on the spring contact
finger or the small spacers on the circuit board mounting screws. It is important that the
operating position of this part be properly maintained for correct contact with the dc
contact on the element body. Also take special care not to disturb the setting of the
potentiometers on the circuit board. These potentiometers are for calibration purposes
and the accuracy of the unit will be altered if the setting of these potentiometers is
changed.
Maintenance
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