Simpson 260 Series - Page 28

4. Zero Ohms:
5. Circuit Jacks:
2
6. Pointer Adjust
For Zero:
7. Reset Button:
Controls, Jacks and Indicators
ohm-meter battery voltage at the (+) pos jack is iden-
tical to the function switch polarity setting and oppo-
site at the (—) common jack.
Off/Transit Position: This function switch position
opens the 260-7P common and 4- jack inputs to avoid
accidental instrument overload or internal battery
drain, additionally to the sensitive instrument damp-
ing during transportation and non-use periods.
This control is used to compensate for variation in
the voltage of the internal batteries.
There are eight jacks on the front panel marked with
the functions they represent (Figure 3-1). These jacks
provide the electrical connections to the test leads.
The COMMON (—) jack is used (in conjunction with
the black test lead) as the reference point for the
measurement of all the functions with the exception
of the 10A range. (Refer to the Operation Section for
details.)
With the Volt-Ohm-Milliammeter in an operating po-
sition, check that the pointer indicates zero at the left
end of the scale when there is no input. If pointer is
off zero, adjust the screw located in the cover below
the center of the dial. Use a small screwdriver to turn
the screw slowly clockwise or counterclockwise until
the pointer is exactly over the zero mark at the left
end of the scale. With the indicating pointer set on
the zero mark, reverse the direction of rotation of the
zero adjuster. Rotate the zero adjuster a sufficient
amount to introduce mechanical freedom or "play"
but insufficient to disturb the position of the indicat-
ing pointer. This procedure will avoid disturbances
to the zero setting by subsequent changes in tempera-
ture, humidity, vibration; and other environmental
conditions.
The white button to the right of the +1V jack is the
reset button of the overload protection circuit.
3-3