Simpson 260 - Accuracy - Model 260; Accuracy - Model 270; D.C. Ranges Accuracy; A.C. Ranges Accuracy

13
3 CONTROLS, JACKS AND INDICATORS
3.1 General
The functions of all the controls, jacks and indicators used to operate the Simpson
260-8 are described in this section. Become familiar with each item prior to oper-
ating the Instrument.
3.2 Front Panel Description
Figure 3-1 depicts the front panel controls, jacks and indicators described below.
1. Front Panel: The 260-8 Volt-Ohm-
Milliammeter is a large, easy-to-read
4¼ inch indicating Instrument. Be-
low the Instrument are four controls
and eight circuit jacks.
2. Range Switch: This switch may
be rotated in either direction to se-
lect any one of the available voltage,
current, or resistance ranges.
3. Function Switch: The function
switch has four positions: Off, +DC,
–DC, and AC Volts Only. To measure
DC current or voltage, set the func-
tion switch at the –DC or +DC posi-
tion, depending on the polarity of the
input signal. To measure AC voltage
set the function switch to the AC po-
sition. For resistance measurement,
the switch may be set in either the
+DC or –DC position. The polarity of
the test voltage will be as marked at
the jacks when the switch is in the +DC position and reversed in the –DC position.
Set this switch to off when not using the meter to take measurements.
4. Zero Ohms: This control is used when measuring resistance to calibrate the
ohms range selected to read zero with the test leads shorted. Refer to paragraph
4.20.
5. Circuit Jacks: There are eight jacks on the front panel marked with the
functions they represent. These jacks provide the electrical connections to the
test leads. The COMMON (–) jack is used as the reference point for the measure-
ment of all the functions with the exception of the 10A range. (Refer to the Opera-
tion Section for details.)
6. Pointer Adjust For Zero: This control is used to mechanically zero the Instru-
ment. With the function switch set to an operating position (+DC, –DC, or AC volts
only), and no applied input, the pointer should read zero. If it does not, use a
screwdriver to turn this adjustment until it does. Once this adjustment is made,
back off slightly so the pointer will rest freely over the zero mark.
FIGURE 3-1. Front Panel Controls, Jacks
and Indicators
D.C.
D.C.
500 MA.
2.5 V.
10 V.
1V.
25 V.
50 A.
AMPS.
250 V.
500 V.
I000 V.
100MA.
10MA.
AMPS.
1MA.
R x 1
R x I0,000
ZERO OHMS
-10 A.
OUTPUT
350 VDC
MAX.
+
COMMON
-
A.C. VOLTS
ONLY
- D.C.
+ D.C.
OFF
A.C
.
A
.C.
O
HM
S
OHMS
2.5
V
.A.
C.
DB
260
ALL TERMINALS 1 V MAX
1
6
4
2
5
3
R X I00
500 V.
A.C. D.C.
1000 V.
A.C. D.C.
+1V.
+10A
50
AMPS.
250 MV.
+