Simpson Electric Company 260-8RT, 260-8 User manual

Simpson 260® Series 8
Volt-Ohm-Milliammeters
INSTRUCTION MANUAL

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

About this Manual

To the best of our knowledge and at the time written, the information contained in
this document is technically correct and the procedures accurate and adequate to
operate this instrument in compliance with its original advertised specifications.

Notes and Safety Information

This Operator’s Manual contains warning headings which alert the user to check
for hazardous conditions. These appear throughout this manual where applicable,
and are defined below. To ensure the safety of operating performance of this in­strument, these instructions must be adhered to.

Warning, refer to accompanying documents.

Caution, risk of electric shock.

Warranty and Returns

SIMPSON ELECTRIC COMPANY warrants each instrument and other articles
manufactured by it to be free from defects in material and workmanship under
normal use and service, its obligation under this warranty being limited to making
good at its factory or other article of equipment which shall within one (1) year
after delivery of such instrument or other article of equipment to the original pur­chaser be returned intact to it, or to one of its authorized service centers, with
transportation charges prepaid, and which its examination shall disclose to its
satisfaction to have been thus defective; this warranty being expressly in lieu of all
other warranties expressed or implied and of all other obligations or liabilities on
its part, and SIMPSON ELECTRIC COMPANY neither assumes nor authorizes
any other persons to assume for it any other liability in connection with the sales
of its products.

This warranty shall not apply to any instrument or other article of equipment which
shall have been repaired or altered outside the SIMPSON ELECTRIC COMPANY
factory or authorized service centers, nor which has been subject to misuse, neg­ligence or accident, incorrect wiring by others, or installation or use not in accord
with instructions furnished by the manufacturer.

®

is a Registered Trademark of the Simpson Electric Co.

260

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

2

Contents

1 INTRODUCTION ................................................................................. 6

1.1 General Description ............................................................................. 6

1.2 Overload Protection .............................................................................6

1.3 Internal Batteries .................................................................................. 7

1.4 Printed Circuit .......................................................................................7

1.5 Phenolic Case ....................................................................................... 7

1.6 Adjust-A-Vue Case ................................................................................ 7

1.7 Test Leads .............................................................................................7

1.8 Technical Data .......................................................................................8

1.9 Definition of Accuracy .......................................................................... 9

1.10Safety Considerations .......................................................................... 9

2 INSTALLATION ................................................................................. 12

2.1 General ................................................................................................ 12

2.2 Unpacking and Inspection ................................................................. 12

2.3 Warranty .............................................................................................. 12

2.4 Power Source Requirements ............................................................. 12

2.5 Operating Position ..............................................................................12

3 CONTROLS, JACKS AND INDICATORS ......................................... 13

3.1 General ................................................................................................ 13

3.2 Front Panel Description ..................................................................... 13

4 OPERATION ..................................................................................... 14

4.1 General ................................................................................................ 14

4.2 Safety Precautions ............................................................................. 14

4.3 Polarity Reversing .............................................................................. 15

4.4 Measurement of Unknown Voltage or Current ................................. 15

4.5 Test Leads ........................................................................................... 15

4.6 DC Voltage Measurement 0-250mV Range ....................................... 16

4.7 DC Voltage Measurement 0-1V Range ............................................... 16

4.8 DC Voltage Measurement 0-2.5 ~ 0-250V Range .............................. 17

4.9 DC Voltage Measurement 0-500V Range ........................................... 17

4.10DC Voltage Measurement 0-1000V Range .........................................18

4.11AC Voltage Measurement 0-2.5 ~ 0-250V Range .............................. 19

4.12AC Voltage Measurement 0-500V Range ........................................... 20

4.13AC Voltage Measurement 0-1000V Range ........................................21

4.14Output Voltage Measurement ............................................................. 22

4.15Decibel Measurement (–20 to +50 dB) ............................................. 23

4.16Direct Current Measurement ............................................................. 23

4.17Direct Current Measurement 0-50μA Range .................................... 24

4.18Direct Current Measurement 0-1mA through 0-500mA range ........ 24

4.19Direct Current Measurement 0-10A range ........................................ 24

4.20Resistance Measurements .................................................................25

4.21Measuring Resistance ........................................................................ 26

4.22Resistance Measurement of Semiconductors ................................. 26

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

4

5 OPERATOR MAINTENANCE ......................................................... 27

5.1 General ................................................................................................ 27

5.2 Inspection ............................................................................................ 27

5.3 Battery Replacement .......................................................................... 28

5.4 Fuse Replacement .............................................................................. 28

5.5 Test Lead Inspection .......................................................................... 28

5.6 Care ...................................................................................................... 29

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

5

1 INTRODUCTION

1.1 General Description

The Simpson Volt-Ohm-Milliammeter 260 Series 8, (hereafter referred to as the
260 or as the Instrument) is a rugged, accurate, compact, easy-to-use Instrument
equipped with mirrored dial to eliminate parallax. The Instrument can be used to
make accurate measurements of AC and DC voltage, direct current, resistance,
decibels, and Output Voltage. The Output Voltage function is used for measuring
the AC component of a mixture of AC and DC voltage. This occurs primarily in
amplifier circuits.

New Features in the 260-8 are:

0-25V AC/DC Range
Mirrored Dial

1.2 Overload Protection

No single protective device nor even a combination of devices as found in the 260
can fully protect a multi-purpose Instrument under all overload conditions. Over­loads of such severity as to damage the Instrument despite all the built-in protec­tion provided are possible when the Instrument is misused. The 260-8 has been
designed to afford maximum instrument protection under overload conditions which
might occur within the measuring capabilities of the Instrument, however, the op­erator must exercise care to avoid severe overloads, particularly when working in
high voltage circuits.

Basic overload protection is provided by a small inexpensive and easily obtain­able 3 AG type, 1 Amp, quick-blow fuse. This fuse is rated to interrupt circuit
voltages up to 250 V. For maximum protection it is important to replace the 1A
fuse with the Littlefuse type 312001 only.

A supplemental high energy fuse is provided for additional protection from severe
overloads. This fuse is rated for an interruption capacity of 10,000 Amps up to
600 V. (Littlefuse Type BLS or Bussman Type BBS). If the Instrument fails to
indicate a reading, the 1 Amp or the 2 Amp fuse may be burned out. (Refer to
paragraph 5.4 for fuse replacement.) A 1 Amp spare fuse is furnished with each
Instrument. Fuses are located in the battery and fuse compartment.

NOTE: The 0-10A range is not fused. The shunt connects directly to
the –10A and +10A jacks.

Two diodes connected across the meter movement affords protection to the move­ment by circumventing excessive current around the movement in the event of an
overload.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

6

1.3 Internal Batteries

There are two batteries in the ohmmeter circuits. One is a NEDA 13F size D cell
that furnishes 1.5-volts for the R X 1 and R X 100 ranges. A NEDA 1604 battery
furnishes 9-volts for the R X 10,000 range. The 1.5-volt D cell is held in place with
two spring clips which also serve as battery contacts. The polarity symbols for the
D cell are marked near the battery contacts. The 9-volt battery is held in place
with a spring clip, but contact is made with a separate connector that is polarized.
Always observe correct polarity when replacing the 1.5-volt D cell.

1.4 Printed Circuit

Most of the component parts are mounted on a printed circuit board which simpli­fies assembly and maintenance, thus, extending the useful life of the Instrument.

1.5 Phenolic Case

The phenolic case is designed with heavy reinforced walls for maximum durability
and provides excellent protection for the circuit components. Access to the bat­teries and fuses are obtained by unscrewing a single captivated screw at the
bottom of the case and sliding out the compartment cover. Rubber plug bumpers
on the bottom of the case reduce sliding should the 260 be accidentally pulled by
the test leads when the Instrument is on a workbench.

1.6 Adjust-A-Vue Case

A carrying handle is attached to the Instrument case. The handle may be used to
support the Instrument in a convenient sloping position for easy viewing. The
case can also be placed in either a vertical or horizontal position. The horizontal
position is preferable for greater accuracy since the Instrument is calibrated in this
position.

1.7 Test Leads

Each Instrument is furnished with one pair (Catalog Number 00043) of probe type
test leads (one red and one black, each 48 inches long) for all applications of the
Instrument. These test leads have elbow prods on one end, to connect the leads
to the recessed jacks on the Instrument front panel. The probe tips at the oppo­site end have threaded shoulders to accept the screw-on insulated alligator clips
(furnished with the test leads) or the 5000 volt test probe(s) to extend the Instru­ment AC or DC voltage range. The test leads and the insulated alligator clips are
rated for the voltage and current ranges available on the 260. Maximum ratings
are 1000V AC or DC or 10 DC amperes.

• THESE RATINGS FOR THE TEST LEADS MUST NOT BE EXCEEDED IN
ANY APPLICATION.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

7

1.8 Technical Data

Table 1-1 lists the technical data for the 260-8.

TABLE 1-1. Technical Data

1. DC VOLTS:
Ranges: 0-1-2.5-10-25-50-250-500-1000V
Sensitivity: 20,000 ohms per volt

2. DC MILLIVOLTS:
Range: 0-250mV
Sensitivity: 20,000 ohms per volt

3. AC VOLTS:
Ranges: 0-2.5-10-25-50-250-500-1000V
Sensitivity: 5,000 ohms per volt

4. OUTPUT VOLTAGE (AC):
Ranges: 0-2.5-10-25-50-250 (limited to 350 VDC)

5. DC MICROAMPERES:
Range: 0-50μA
Voltage Drop: 250mV

6. DC MILLIAMPERES:
Ranges: 0-1-10-100-500 mA
Voltage Drop (Approx.): 250 mV, 255 mV, 300 mV, 500 mV

7. DC AMPERES:
Range: 0-10A
Voltage Drop (Approx.): 255 mV

NOTE: The 10A range is not internally fused.

8.

ECNATSISE1RX0R01X0R00,01XR

egna 1R000,2- 10000,002- 10M02-0

gnidaeRretne 1C211002 11000,021

nepOlanimoN
egatloVtiucriC

trohSlanimoN
tnerruCtiucriC

V5.1V

Am52A1m52.A1 μ57

9. * ACCURACY:
DC Voltage Ranges: 2% of Full Scale
DC Current:
0-50 μA Range: 1.5% of Full Scale
Other Ranges: 2% of Full Scale
**AC Voltage Ranges: 3% of Full Scale
Frequency Response: Referenced to 100 Hz (Figures 4-4 and 4-9)
Resistance Ranges:
R X 1: 2.5° of Arc
R X 100: 2° of Arc
R X 10,000: 2° of Arc

* Accuracies specified are for the 260 in a horizontal position.

5.1V9

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

8

10. DECIBELS:
Range: –20 to +10 dB, –8 to +22 dB, 0 to +30 dB,

+6 to +36 dB, +20 to +50 dB

Reference Level: With zero dB power level equal to 1 mW across a

600V line.

11. BATTERIES:
Voltage: 1.5V, 9V
NEDA No.: 13F, 1604

12. FUSE: F1 1A, 250V, type 3AG, quickacting Littlefuse Type

312001, F2 2A, 600V Littlefuse Type BLS or 2A
600V, Bussman Type BBS.

13. TEST LEADS: 1 red, 1 black, 48" long.

14. SIZE: 5½” x 7" x 3 ” (13.34 x 17.78 x 7.94 cm)

15. WEIGHT: 3 lbs. (1.359 kg)

16. RATED-CIRCUIT-TO­GROUND VOLTAGE: 1000V AC/DC Max.

***Per ANSI C 39.5 April 1974: “The specified voltage with respect to ground, which may be safely and continuously
applied to the circuit of an Instrument.”

1.9 Definition of Accuracy

The voltage and current accuracy of this Instrument is commonly expressed as a
percent of full scale. This should not be confused with accuracy of reading (indi­cation). For example, +2% of full scale on the 10 volt range allows an error of
±0.20V at any point on the dial. This means that at full scale, the accuracy read­ing would be ±2%, but at half scale it would be ±4%. Therefore, it is advantageous
to select a range which gives an indication as near as possible to full scale.

1.10 Safety Considerations

This Operator’s Manual contains cautions and warnings alerting the user to haz­ardous operating and service conditions. This information is flagged by CAUTION
or WARNING headings throughout the publication, where applicable, and is de­fined at the front of the manual under SAFETY SYMBOLS. To ensure the safety of
operating and servicing personnel and to retain the operating conditions of the
Instrument, these instructions must be adhered to.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

9

TABLE 1-2. Items and Accessories Furnished with this Instrument

Quantity

1

*1

*1

2

1

1

Description

Test Lead Set – one red and one black (4 ft. long) each with
combination probe tip and removable rubber-sleeved alligator
clip.

1.5 Volt, D Cell, NEDA 13F

9.0 Volt Cell, NEDA 1604

1 Amp, 250V Fuse, Littlefuse Type #312001

2A, 600V Fuse, Littlefuse Type BLS or (Bussman Type BBS)

Operator’s Manual

TABLE 1-3. Additional Accessories

Number

00043

6-114338

Deluxe Case .................................................................................................. 00812

Model 150-2 Amp-Clamp .............................................................................. 00545

Accessory AC High Voltage Probe

The 10,000 V AC accessory probe is similar to the high voltage DC probes with
the following exceptions: The AC high voltage probe is designed to extend the
260-8 AC voltage range. The probe can be used with the Simpson 260-8 10-volt
AC range.

NOTE: Instructions are furnished with each high voltage probe.

AMP-CLAMP MODEL 150-2

rebmuN golataCnoitpircseD

The Simpson Amp-Clamp Model 150-2 allows AC current measurements without
breaking the circuit under test. The Amp-Clamp works in effect as a transformer
containing a split core for accommodating the conductor which carries the current
being measured. The current carrying conductor becomes the transformer pri-

10

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

mary and a coil in the Amp-Clamp serves as the secondary winding. The Amp­Clamp output voltage is proportional to the current measured and can be applied
to the 260-8 as an AC voltage.

The Amp-Clamp has a range selector with 6 positions. Any of the following cur­rent ranges can be used with the 260-8:

5, 10, 25, 50, 100 or 250 amperes.

NOTE: Instructions are furnished with each Amp-Clamp.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

11

2 INSTALLATION

2.1 General

This section contains information and instructions for the installation and shipping
of the Simpson 260-8. Included are unpacking and inspection procedures, war­ranty, shipping, power source requirements and operating position.

2.2 Unpacking and Inspection

Examine the shipping carton for obvious signs of damage. If damage is noted,
notify the carrier and supplier and do not attempt further use of the Instrument. If
Instrument appears to be in good condition, read Operator’s Manual in its entirety.
Become familiar with the Instrument as instructed in the manual, then proceed to
check the electrical performance as soon as possible. Also, check that all items
listed in Table 1-2 are included with the Instrument.

After unpacking the Instrument, a 1.5V battery and a 9V battery may be found in
separate envelopes in the box with the Instrument and the test leads. Two alliga­tor clips for the test leads are in a polyethylene bag. (See Section V for instruc­tions on how to open the battery compartment and install the batteries.)

2.3 Warranty

The Simpson Electric Company warranty policy is printed in the front of this manual.
Read it carefully prior to requesting any warranty repairs. For assistance of any
kind, including help with the Instrument under warranty, contact the nearest Au­thorized Service Center for instructions. If it is necessary to contact the factory
directly, give full details of any installation difficulty and include the Instrument
model number, series number, and date of purchase. Service data or shipping
instructions will be mailed promptly. If an estimate of charges for non-warranty or
other service work is required, a maximum charge estimate will be quoted. This
charge will not be exceeded without prior approval. Pack the Instrument carefully
and ship it prepaid and insured to the proper destination.

2.4 Power Source Requirements

There are two batteries in the ohmmeter circuits: One is a NEDA 13F D size cell
that furnishes 1.5 volts for the R X 1 and R X 100 ranges. A NEDA 1604 battery
furnishes 9 volts for the R X 10,000 range. The 1.5 volt D cell is held in place with
two spring clips which also serve as battery contacts. The 9-volt battery is held in
place with a spring clip but contact is made with a separate connector that is
polarized. (Always observe correct polarity when replacing the 1.5-volt D cell.)

2.5 Operating Position

A handle is attached to the side of the Instrument case. The handle may be used
to support the Instrument in a convenient, sloping position for easy viewing. The
VOM case can also be placed either in a vertical or horizontal position. The
horizontal position is preferable for greater accuracy since the Instrument is cali­brated in this position.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

12

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 oper­ating 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-

O

HM

OHMS

D.C.

.

C.

A.C

.A.

V

2.5

1

DB

S

D.C .

A

.C.

Milliammeter is a large, easy-to-read
4¼ inch indicating Instrument. Be­low the Instrument are four controls
and eight circuit jacks.

2. Range Switch: This switch may

6

be rotated in either direction to se­lect any one of the available voltage,
current, or resistance ranges.

-10 A.

OUTPUT

350 VDC

MAX.

+

500 MA.

2.5 V.

10 V.

1V.

25 V.

50 A.

AMPS.

250 V.

500 V.
I000 V.

ALL TERMINALS 1 V MAX

A.C. VOLTS

ONLY

- D.C.

3

+ D.C.

OFF

COMMON

-

260

100MA.

R X I00

R x I0,000

10MA.

1MA.

R x 1

AMPS.

+1V.

500 V.

A.C. D.C.

+

ZERO OHMS

+10A

50

250 MV.

1000 V.

A.C. D.C.

AMPS.

3. Function Switch: The function
switch has four positions: Off, +DC,

4

–DC, and AC Volts Only. To measure
DC current or voltage, set the func­tion switch at the –DC or +DC posi­tion, depending on the polarity of the
input signal. To measure AC voltage
set the function switch to the AC po-

5

2

FIGURE 3-1. Front Panel Controls, Jacks

and Indicators

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 measure­ment of all the functions with the exception of the 10A range. (Refer to the Opera­tion Section for details.)

6. Pointer Adjust For Zero: This control is used to mechanically zero the Instru­ment. 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.

13

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

4 OPERATION

Multi-function instruments (VOM’s) such as the 260-8 are intended
as general purpose measuring Instruments for use in low power cir­cuitry such as found in consumer appliances, TV and radio receivers,
and in general laboratory applications. Their use is not recommended
in high voltage, high power circuitry where operator errors and inad­equate personal protective measures could result in serious injury
from arcing or explosion. Such circuitry is found in industrial or com­mercial applications such as induction (r-f) heaters and broadcast
transmitters, power substations and distribution centers, x-ray equip­ment, large motor controls and the like. Working in the high voltage
section of such equipment requires single-function, often specially
designed instruments used by specially trained personnel using ap­propriate protective equipment and procedures.

4.1 General

This section of the manual contains information required to use and operate the
260-8 in a safe and proper manner.

4.2 Safety Precautions

The following precautions are suggestions and reminders of commonly recog­nized safe practices and specific hazards to be avoided and are not implied to be
sufficient to ensure the safety of untrained personnel in all circumstances. Nei­ther is this manual a substitute for technical manuals covering the equipment in
which measurements are to be made. Always refer to the equipment manual and
its specific warnings and instructions and observe them as well as those con­tained herein.

a. The 260-8 should only be used by personnel qualified to recognize shock

hazards and trained in the safety precautions required to avoid possible in­jury.

b. Do not connect any terminal of this Instrument to a circuit point at which a

voltage exceeding 1000 volts AC or DC may exist with respect to earth ground.
(Refer to Table 1-1, item 16.)

c. Turn off power and discharge any capacitors in the circuit to be measured

before connecting to or disconnecting from it.

d. Prior to using this Instrument, check accessories (if any) and test leads for

missing, damaged, deteriorated or otherwise faulty insulating parts. Do not
use, or permit the use of equipment with faulty insulation until it has been

properly repaired.
e. Always wear safety glasses when working in electrical circuitry.
f. Do not work alone on high voltage circuits. Make certain that someone ca-

pable of rendering aid is nearby and watchful.
g. Do not handle the Instrument, its test leads, or the circuitry while high voltage

is being applied.
h. Hands, shoes, floor, and workbench must be dry. Avoid making measure-

ments under humid, damp, or other environmental conditions that could ef-

fect the dielectric withstanding voltage of the test leads or Instrument.
i. Do not change switch settings or test lead connections while taking measure-

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

14

ments. A mistake could result in damage to the Instrument and possible

personal injury.
j. Locate all voltage sources and accessible current paths before making con-

nections to circuitry. High voltage may appear unexpectedly or in unexpected

locations in faulty equipment. An open bleeder resistor, for example, may

result in a capacitor retaining a dangerous charge.
k. Make certain that the equipment being worked upon is properly grounded

and fuses are of the proper type and rating.
l. Check and double check switch positions and jack connections before apply-

ing power to the Instrument.
m. Always remain alert for low voltage circuits which may be floating at high

voltage with respect to earth ground and for composite voltages (AC + DC)

such as are found in r-f amplifiers. The floating voltage or composite voltage

must not exceed the Instrument’s rated maximum circuit-to-ground voltage.
n. Do not make electrical measurements where the air may contain explosive

concentrations of gas or dust such as in mines, grain elevators, gasoline

stations or in the presence of charging batteries until determined to be safe

by qualified personnel. Note that even metallic dusts can be explosive.
o. No General Purpose VOM is to be used to make electrical measurements on

blasting circuits or blasting caps. Use only VOM’s designed for this purpose.

4.3 Polarity Reversing

The function switch provides a convenient means to reverse polarity of the inter­nal battery to facilitate testing semiconductor devices. The +DC and –DC posi­tions transpose internal connections to the COMMON and +jacks and therefore
can also be used to reverse polarity of external voltages and currents connected
to these jacks (only). Because polarity reversing momentarily interrupts the cir­cuit, it should not be done while measuring current or voltage without first turning
off the circuit power. When making measurements on the 50mA/250mV, 1 volt, or
10 amp range, polarity can be corrected only by reversing the test leads.

4.4 Measurement of Unknown Voltage or Current

Sometimes the approximate voltage or current to be measured is known and the
correct range may easily be selected. It is often the case, however, particularly
when working upon faulty equipment, when the voltage or current is either un­known or may be much higher than normal and anticipated. Whenever working
upon unfamiliar or unknown equipment, always begin a measurement using the
highest range available on the Instrument. Once it is determined that the voltage
is within the limits of a lower range, change to the lower range.

4.5 Test Leads

These are provided with accessory screw-on alligator clips which may be attached
to the probe tips. Aside from the convenience of eliminating the need to hand­hold test prods to a circuit for extended periods, the test clips provide a means of
reducing hand proximity to a high voltage circuit while energized. Circuit power
must of course be turned off and any charged capacitors discharged before con­necting or disconnecting clips to or from the current.

15

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

4.6 DC Voltage Measurement 0-250mV Range

Prior to making voltage measurements, review the SAFETY PRE-

CAUTIONS listed in paragraph 4.2. Also, when using the 260 as a

millivoltmeter, care must be taken to prevent damage to the indicat-

ing instrument from excessive voltage. Before using the 250 millivolt

range, use the 1.0-volt DC range to determine that the voltage mea-

sured is not greater than 250 millivolts (or .25 volt DC).

a. Set the function switch at +DC (Figure 4-1).
b. Plug the black test lead in the – COMMON jack and the red test lead into the

+50 μA/250mV jack.
c. Set the range switch at 50 μA (common position with 50V).
d. Connect the black test lead to the negative side of the circuit being measured

and the red test lead to the positive side of the circuit.
e. Read the voltage on the black scale marked DC and use the figures marked

0-250. Read directly in millivolts.

NOTE: For polarity reversing see paragraph 4.3.

4.7 DC Voltage Measurement 0-1V Range

D.C .

+10A

+1V.

AMPS.

50

+

250 MV.

- D.C.

+ D.C.

COMMON

-

.

D.C

2.5 V.

10 V.

1V.

25 V.

50 A.

AMPS.

250 V.

500 V.
I000 V.

+

260

ALL TERMINALS 1 V MAX

Figure 4-1. Jacks and Switch Positions

for Measuring DC Voltages, 0 through

250V Ranges

a. Set the function switch at +DC (Figure 4-

1).

b. Plug the black test lead into the – COM-

MON jack and the red test lead into the
+1V jack.

c. Set the range switch at 1V (common po-

sition with 10V).

d. Connect the black test lead to the nega-

tive side of the circuit being measured
and the red test lead to the positive side
of the circuit.

e. Read the voltage on the black scale

marked DC and use the figures marked
0-10. Then divide the reading by 10.

NOTE: For polarity reversing see paragraph 4.3.

16

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

4.8 DC Voltage Measurement 0-2.5 ~ 0-250V Range

a. Set the function switch at +DC (Figure 4-1).
b. Plug the black test lead into the – COMMON jack and the red test lead into

the + jack.
c. Set the range switch at one of the five voltage range positions marked 2.5V,

10V, 25V, 50V or 250V.

NOTE: When in doubt as to the voltage present, always use the highest voltage
range as a protection to the Instrument. If the voltage is within a lower range, the
switch may be set for the lower range to obtain a more accurate reading. Be sure
power is off in the circuit being measured and all capacitors discharged.

d. Connect the black test lead to the negative side of the circuit being measured

and the red test lead to the positive side of the circuit.
e. Turn on the power in the circuit being measured.
f. Read the voltage on the black scale marked DC. For the 2.5V range, use the

0-250 figures and divide by 100. For the 10V, 50V, and 250V ranges, read the

figures directly. For the 25V range, use the 0-250 figures and divide by 10.

NOTE: Turn off power to the circuit and wait until the meter indicates zero before
disconnecting the test leads.

4.9 DC Voltage Measurement 0-500V Range

!

Be extremely careful when working with high voltage circuits. Do not
touch the Instrument or test leads while power is on in the circuit being
measured.

Before proceeding with the following steps, re­view the Safety Precautions in 4.2.

a. Set the function switch at +DC (Figure 4-

2).

b. Set the range switch at the 250V/500V/

1000V position.

c. Plug the black test lead into the – COM-

MON jack and the red test lead into the
500V jack.

d. Be sure power is off in the circuit being

measured and all capacitors discharged.
Connect the black test lead to the nega­tive side of the circuit being measured and
the red test lead to the positive side of the

circuit.
e. Turn on power in circuit being measured.
f. Read the voltage using the 0-50 figures

on the black scale marked DC. Multiply

the reading by 10.

NOTE: Turn off power to the circuit and wait
until the meter indicates zero before
disconnecting the test leads.

500 V.

A.C. D.C.

D.C

.

- D.C.

+ D.C.

COMMON

-

.

D.C

250 V.

500 V.
I000 V.

260

ALL TERMINALS 1 V MAX

FIGURE 4-2. Jacks and Switch

Positions for Measuring DC Voltage,

0-500V Range

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

17

4.10 DC Voltage Measurement 0-1000V Range

!

Be extremely careful when working with high voltage circuits. Do not
touch the Instrument or test leads while power is on in the circuit being
measured.

Before proceeding with the following steps, review the Safety Precautions in 4.2.

a. Set the function switch at +DC (Figure 4-

1).

b. Set the range switch at the 250V/500V/

1000V position.

D

.C.

1000 V.

A.C. D.C.

c. Plug the black test lead into the – COM-

MON jack and the red test lead into the
1000V jack.

d. Be sure power is off in the circuit being

measured and all capacitors discharged.
Connect the black test lead to the nega­tive side of the circuit being measured
and the red test lead to the positive side

of the circuit.
e. Turn on power in circuit being measured.
f. Read the voltage using the 0-10 figures

on the black scale marked DC. Multiply

the reading by 100.

- D.C.

+ D.C.

COMMON

-

.

D.C

250 V.

500 V.
I000 V.

260

ALL TERMINALS 1 V MAX

FIGURE 4-3. Jacks and Switch Positions

for Measuring DC Voltage, 0-1000V

Range

+5

+4

+3

+2

+1

0

-1

-2

PERCENT RELATIVE ERROR

-3

-4

-5

10Hz 100Hz 1KHz 10KHz 100KHz

AC VOLTAGE RANGES

2.5 VAC RANGE
10VAC RANGE

50 VAC RANGE
250 VAC RANGE
500 VAC RANGE

1000 VAC RANGE

FREQUENCY

NOTE: Turn off power to the circuit and
wait until the meter indicates zero before
disconnecting the test leads.

A.C.

A.C. VOLTS

ONLY

COMMON

C.

.

A.

V.A.C

.5

2

2.5 V.

10 V.

1V.

25 V.

50 A.

AMPS.

250 V.

500 V.
I000 V.

+

-

260

ALL TERMINALS 1 V MAX

FIGURE 4-4. Frequency Response, AC

Voltage Ranges

FIGURE 4-5. Jacks and Switch Positions

for Measuring AC Voltage 0-2.5 through

0-250V Ranges

18

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

4.11 AC Voltage Measurement 0-2.5 ~ 0-250V Range

!

Branch and distribution circuits (120/240/480V etc.) can deliver dan­gerous explosive power momentarily into a short circuit before the
fuse/breaker opens the circuit. Make absolutely certain that the In­strument switches are set properly, jacks are connected properly, and
that the circuit power is turned off before making connections to such
circuits.

The 260 responds to the average value of an AC waveform. It is calibrated in
terms of the RMS value of a pure sine wave. If the waveform is nonsinusoidal, and
depending upon its waveform, the reading may be either higher or lower than the
true RMS value of the measured voltage. Thus an error may be introduced if the
260 is used to measure a nonsinusoidal waveform. Also, accuracy is lessened at
higher input frequencies (Figure 4-4).

Before proceeding with the following steps, review the Safety Precautions in Para­graph 4.2.

a. Set the function switch to AC Volts Only position (Figure 4-5).

NOTE: The meter will not indicate if the switch is incorrectly set to a DC position.

b. Set the range switch at one of the five voltage range positions marked 2.5V,

10V, 25V, 50V or 250V. (When in doubt as to actual voltage present, always
use the highest voltage range as a protection to the Instrument. If the voltage
is within a lower range, the switch may be set for the lower range to obtain a
more accurate reading.)

50

.

A.C

A.C.

A.C.

10

A.C.

A.C. VOLTS

ONLY

COMMON

-

2.5 V.

10 V.

1V.

25 V.

50 A.

AMPS.

250 V.

500 V.
I000 V.

ALL TERMINALS 1 V MAX

260

500 V.

A.C. D.C.

ZERO OHMS

FIGURE 4-6. Jacks and Switch Positions

for Measuring AC Voltage 0-2.5 Through

0-250V Ranges

A.C. VOLTS

ONLY

COMMON

-

2.5 V.

10 V.

1V.

25 V.

50 A.

AMPS.

250 V.

500 V.
I000 V.

ALL TERMINALS 1 V MAX

260

500 V.

A.C. D.C.

ZERO OHMS

FIGURE 4-7. Jacks and Switch

Positions for Measuring AC Voltage 0

Through 1000V Range

19

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

c. Plug the black test lead into the – COMMON jack and the red test lead into

the + jack.

d. Turn off power to the circuit to be measured and discharge any capacitors.
e. Connect the test leads across the circuit voltage to be measured with the

black lead to the grounded side.

f. For the 2.5V range read the value directly on the scale marked 2.5 VAC. For

the 10V, 25V, 50V and 250V ranges, read the red scale marked AC and use
the black figure immediately above the scale.

4.12 AC Voltage Measurement 0-500V Range

Be extremely careful when working in high voltage circuits. Do not handle the
Instrument or test leads while the circuit being measured is energized. OBSERVE
ALL SAFETY PRECAUTIONS in paragraph 4.2 and in the instruction manual for
the equipment being tested.

Do not attempt any voltage measurement which may exceed 1000
volts or the circuit-to-ground voltage of the Instrument, 1000 volts
maximum.

Be sure that the range switch is set to the 250V/500V/1000V range,
function switch to AC volts only position, and test leads connected
to common and 500V jack.

Do not touch the Instrument or test leads while the power is on the
circuit being measured.

Before proceeding with the following steps, review the Safety Precautions in Para­graph 4.2.

a. Set the function switch to AC Volts Only position (Figure 4-6).

When making AC voltage measurements with the function switch
incorrectly set to DC, the Instrument pointer will remain at or near
zero, indicating a false “no voltage present” condition that could be
hazardous.

b. Set the range switch at 250V/500V/1000V position.
c. Plug the black test lead into the – COMMON jack and the red test lead in the

500V jack.

d. Be sure the power is off in the circuit being measured and that all its capaci-

tors have been discharged.

e. Connect the test leads across the circuit voltage to be measured with the

black lead to the grounded side.

f. Turn on the power in the circuit being measured.
g. Read the voltage on the red scale marked AC. Use the 0-50 figures and

multiply by 10.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

20

4.13 AC Voltage Measurement 0-1000V Range

Be extremely careful when working in high voltage circuits. Do not
handle the Instrument or test leads while the circuit being measured
is energized. OBSERVE ALL SAFETY PRECAUTIONS in paragraph

4.2 and in the instruction manual for the equipment being tested.
Do not attempt any voltage measurement which may exceed 1000
volts or the circuit-to-ground voltage of the Instrument, 1000 volts
maximum.

Be sure that the range switch is set to the 250V/500V/1000V range,
function switch to AC Volts Only position, and test leads connected
to common and 1000V jack. Do not touch the Instrument or test
leads while the power is on in the circuit being measured.

+10

+8

+6

+4

+2

0

-2

-4

-6

-8

-10

10Hz 100Hz 1KHz 10KHz 100KHz 1MHz

FIGURE 4-8. Frequency Response Output

OUTPUT RANGES

2.5 VAC RANGE

10VAC RANGE

25/50 VAC RANGE

250 VAC RANGE

FREQUENCY

Ranges

A.

C.

A.C. VOLTS

ONLY

COMMON

.

A.C

OUTPUT

350 VDC

MAX.

2.5 V.

10 V.

1V.

25 V.

50 A.

AMPS.

250 V.

500 V.
I000 V.

-

260

ALL TERMINALS 1 V MAX

FIGURE 4-9. Jacks and Switch

Positions for Output Measurements

Before proceeding with the following steps, review the Safety Precautions in Para­graph 4.2.
a. Set the function switch at AC (Figure 4-7).
b. Set the range switch at 250V/500V/1000V position.
c. Plug the black test lead into the -COMMON jack and the red test lead in the

1000V jack.

d. Be sure the power is off in the circuit being measured and that all its capaci-

tors have been discharged.

e. Connect the test leads across the circuit voltage to be measured with the

black lead to the grounded side.

f. Turn on the power in the circuit being measured.
g. Read the voltage on the red scale marked AC. Use the 0-10 figures and

multiply by 100.

21

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

.

D.C

B

D

D.C .

A.C. VOLTS

ONLY

COMMON

-

+

2.5 V.

10 V.

1V.

25 V.

50 A.

AMPS.

250 V.

500 V.
I000 V.

ALL TERMINALS 1 V MAX

260

FIGURE 4-10. Jacks and Switch

Positions for Measuring Decibels.

OUTPUT

350 VDC

MAX.

+

500 MA.

50 A.

AMPS.

ALL TERMINALS 1 V MAX

260

A.C. VOLTS

- D.C.

+ D.C.

ONLY

OFF

COMMON

-

FIGURE 4-11. Jacks and Switch

Positions for Measuring Direct Current

100MA.

10MA.

1MA.

+1V.

AMPS.

-10 A.

4.14 Output Voltage Measurement

It is often desired to measure the AC component of an Output Voltage where both
AC and DC voltage levels exist. This occurs primarily in amplifier circuits. The
260-8 has a 0.1 mfd, 400 volt capacitor in series with the OUTPUT jack. The
capacitor blocks the DC component of the current in the test circuit, but allows the
AC or desired component to pass on to the indicating instrument circuit. The
blocking capacitor may alter the AC response at low frequencies but is usually
ignored at audio frequencies (Figure 4-8).

Do not connect the OUTPUT jack to a circuit in which the DC voltage component
exceeds 350V.

+10A

50

AMPS.

+

250 MV.

Before proceeding with the following steps, review the Safety Precautions in Para­graph 4.2.

a. Set the function switch to AC volts only position (Figure 4-9).
b. Plug the black test lead into the -COMMON jack and the red test lead into the

OUTPUT jack.

c. Set the range switch at one of the range positions marked 2.5V, 10V, 25V,

50V, or 250V.

d. Connect the test leads across the circuit being measured with the black test

lead to the ground side.

e. Turn on the power in the test circuit. Read the output voltage on the appropri-

ate AC voltage scale. For the 0-2.5V range, read the value directly on the
scale marked 2.5 VAC. For the 10V, 25V, 50V, or 250V ranges, use the red
scale marked AC and read the black figures immediately above the scale.

22

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

4.15 Decibel Measurement (–20 to +50 dB)

In some industries, measurements are made in terms of voltage or current ratios
(decibels) based on a specific reference level. The dB scale on the 260-8 serves
this purpose and is calibrated to a reference level (zero dB) of 0.001 watt into 600
ohms. The scale calibration of –20 to +10 dB is for the 0-2.5V range (zero dB =

0.775V). Higher ranges may be used by adding an appropriate dB value to the
reading in accordance with the chart on page 14.

a. Review the safety precautions in paragraph 4.2.
b. Refer to Figure 4-10 for switch settings and jack connections.
c. Use operating instructions for AC VOLTAGE MEASUREMENT, 0-2.5/10/25/

50/250V RANGES (paragraph 4.9).

Do not use the 500V or 1000V ranges for decibel readings.
d. Read decibels on the bottom scale marked dB. For the 10/25/50/250V ranges,

add the appropriate factor from the chart below:

egnaRegatloeVgnaRBgdnidaeR

V5.2-001+ot02y-ltceriddaer

V01-202+ot8g-nidaerotBd21+dda

V52-003otg0nidaerotBd02+dda

V05-603+ot6g

V052-005+ot02g+nidaerotBd04dda

NOTE: The maximum voltage ratio that can be measured is +50 dB
on the 0-250V range.

e. If dB measurements are being made to a 0.006 watt into 500 ohm reference

level, subtract +7 dB from the reading obtained on the 260.

+nidaerotBd62dda

4.16 Direct Current Measurement

• DO NOT CHANGE THE RANGE SETTING OF THE RANGE OR FUNCTION

SWITCHES WHILE THE CIRCUIT IS ENERGIZED.

• NEVER DISCONNECT TEST LEADS FROM THE CIRCUIT UNDER MEA-

SUREMENT WHILE IT IS ENERGIZED.

!

• ALWAYS TURN THE POWER OFF AND DISCHARGE ALL THE CAPACITORS

BEFORE THE SETTING OF THE SWITCHES IS CHANGED, OR THE LEADS
DISCONNECTED.

• NEVER EXCEED THE CIRCUIT-TO-GROUND VOLTAGE OF THE INSTRU-

MENT (1000 V MAX., TABLE 1-1, ITEM 16).

• ALWAYS CONNECT THE INSTRUMENT IN SERIES WITH THE GROUND

SIDE OF THE CIRCUIT.

• IN ALL DIRECT CURRENT MEASUREMENTS, MAKE CERTAIN THE POWER

TO THE CIRCUIT BEING TESTED HAS BEEN TURNED OFF BEFORE CON­NECTING AND DISCONNECTING TEST LEADS OR RESTORING CIRCUIT
CONTINUITY.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

23

4.17 Direct Current Measurement 0-50μA Range

a. Set the function switch at +DC.
b. Plug the black test lead into the –COMMON jack and the red test lead into the

+50μAMPS/250mV jack.

c. Set the range switch at 50μAMPS (dual position with 50V).
d. Open the ground side of the circuit in which the current is being measured.

Connect the VOM in series with the circuit. Connect the red test lead to the
positive side and the black test lead to the negative side.

e. Read the current on the black DC scale. Use the 0-50 figures to read directly

in microamperes.

NOTE: For polarity reversing see paragraph 4.3.

4.18 Direct Current Measurement 0-1mA through 0-500mA
range

a. Set the function switch at +DC (Figure 4-11).
b. Plug the black test lead into the – COMMON jack and the red test lead into

the + jack.

c. Set the range switch at one of the four range positions marked 1 mA, 10 mA,

100 mA or 500 mA.

d. Open the grounded side of the circuit in which the current is being measured.

Connect the VOM in series with the circuit. Connect the red test lead to the
positive side and the black test lead to the negative side.

e. Turn the power on. Read the current in milliamperes on the black DC scale.

For the 1 mA range, use the 0-10 figures and divide by 10. For the 10 mA
range, use the 0-10 figures directly. For the 100 mA range, use the 0-10
figures and multiply by 10. For the 500 mA range, use the 0-50 figures and
multiply by 10.

f. Turn the power off and disconnect the test leads.

This range is only intended for measurements in low voltage circuits
(under 25 V DC) such as the primary power in vehicles or their ac­cessories.

4.19 Direct Current Measurement 0-10A range

a. Plug the black test lead into the –10A jack and the red test lead into the +10A

jack.

b. Set the range switch at 10 AMPS (dual position with 10 mA).
c. Open the ground side of the circuit in which the current is being measured.

Connect the VOM in series with the circuit, connecting the red test lead to the
positive side and the black test lead to the negative side.

NOTE: The function switch has no effect on polarity for the 10 AMPS range.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

24

d. Turn the power on. Read the current directly on the black DC scale. Use the

0-10 figures to read directly in amperes.

e. Turn the power off and disconnect the test leads.

!

The 10A range is not internally fused in the 260-8.

When using the 10A range, never disconnect a test lead from a jack
or from the circuit while the circuit is energized. Doing so may likely
damage the test jacks or leads and the arcing may be hazardous to
the operator. Turn off circuit power and wait for the meter reading to
drop to zero.

The polarity reversing feature of the function switch does not operate
on the 0-10A range. If polarity is found to be incorrect, turn off circuit
power, wait for the meter indication to reach zero and then interchange
test lead connections to the circuit.

4.20 Resistance Measurements

Voltage applied to a resistance range will cause reading errors if low
and damage the Instrument if high. When making in-circuit measure­ments, make certain that the circuit is completely de-energized be­fore making connections to it.

When making in-circuit measurements, circuit paths in parallel with
the resistance being measured may cause reading errors. Check
circuit diagrams for the presence of such components before assum­ing that the reading obtained is correct.

When resistance is measured, the batteries furnish power for the circuit. Since
batteries are subject to variation in voltage and internal resistance, the Instrument
must be adjusted to zero before measuring a resistance, as follows:

a. Turn range switch to desired ohms range.
b. Plug the black test lead into the –COMMON jack and the red test lead into the

+ jack.

c. Connect the ends of test leads together to short the VOM resistance circuit.
d. Rotate the ZERO OHMS control until pointer indicates zero ohms. If pointer

cannot be adjusted to zero, one or both of the batteries must be replaced.
(For battery replacement, refer to Section V.)

e. Disconnect shorted test leads.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

25

4.21 Measuring Resistance

a. Before measuring resistance in a circuit, make sure the power is off to the

circuit being tested and all capacitors are discharged. Disconnect shunting
components from the circuit before measuring its resistance.

b. Set the range switch to one of the resistance range positions as follows (Fig-

ure 4-12):

1. Use R X 1 for resistance readings from 0 to 200 ohms.

2. Use R X 100 for resistance readings from 200 to 20,000 ohms.

3. Use R X 10,000 for resistance readings above 20,000 ohms.

c. Set the function switch at either –DC or +DC position:

Operation is the same in either position except if there are semicon­ductors in the circuit. (See paragraph 4.22.) Adjust ZERO OHMS
control for each resistance range.

d. Observe the reading on the OHMS scale at the top of the dial.

NOTE: The OHMS scale reads from right to left for increasing values of resis­tance.

e. To determine the actual resistance value, multiply the reading by the factor at

the switch position. (K on the OHMS scale equals one thousand.)

4.22 Resistance Measurement of Semiconductors

Make sure that the OHMS range being used will not damage any of
the semiconductors (refer to Table 1-1, item 8, Section I).

If there is a “forward” and “backward” resistance such as in diodes, the resistance
should be relatively low in one direction (for forward polarity) and higher in the
opposite direction.

Rotate the function switch between the two DC positions to reverse polarity. This
will determine if there is a difference between the resistance in the two directions.
To check a semiconductor in or out of a circuit (forward and reverse bias resis­tance measurements) consider the following before making the measurement:

a. The polarity of the battery voltage will be as marked at the jacks when the

switch is in the +DC position and reversed in the –DC position.

b. Ensure that the range selected will not damage the semiconductor. (Refer to

Table 1-1, item 8, and review the specification limits of the semiconductor
according to the manufacturer’s ratings.)

c. If the semiconductor is a silicon diode or conventional silicon transistor, no

precautions are normally required.

d. If the semiconductor material is germanium, check the ratings of the device

and refer to Table 1-1, item 8.

NOTE: The resistance of diodes will measure differently from one resistance
range to another on the VOM with the function switch in a given position. For
example, a diode which measures 80 ohms on the R X 1 range may measure 300
ohms on the R X 100 range. The difference in values is a result of the diode
characteristics and is not indicative of any fault in the VOM.

26

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

O

HMS

R x 1

- D.C.

+ D.C.

COMMON

-

OHMS

+

260

ALL TERMINALS 1 V MAX

R X I00

R x I0,000

FIGURE 4-12. Jacks and Switch Positions for Measuring Resistance

5 OPERATOR MAINTENANCE

5.1 General

The following paragraphs in this section describe battery replacement, fuse re­placement, and preventive maintenance procedures for the 260-8.

5.2 Inspection

The user is protected from electrical shock by the insulation of the 260 and its test
leads. Frequently examine them for any insulation damage such as cracks, cuts,

chips, burns or deterioration that ex­pose internal metal parts or reduce
the spacing between such metal
parts and hand contact by the opera­tor.

Make certain that the battery com­partment cover is securely fastened
in place before the Instrument is
used.

Do not use an Instrument with a bro­ken meter glass.

FIGURE 5-1. Battery and Fuse Com­partment

Whenever the battery compartment
cover is removed for any reason,
check that the proper fuses are be­ing used.

LAC DU FLAMBEAU, WI

27

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

5.3 Battery Replacement

a. Two batteries are used inside the case to supply power for resistance mea-

surements. One is a 1.5-volt D cell and the other is a 9-volt battery. When it
is no longer possible to adjust the pointer to zero for the R X 1 and R X 100
ranges (refer to ZERO OHMS ADJUSTMENT paragraph 4.20), replace the

1.5-volt cell. When it is no longer possible to adjust the pointer to zero on the
R X 10,000 range, replace the 9-volt battery.

b. To install or replace a battery, de-energize and disconnect test leads from the

Instrument, then remove the cover to the externally accessible battery com­partment by loosening the single captivated screw.

NOTE: Batteries should be replaced before their useful life has expired.
Failure to do so may result in corrosion and battery leakage.

c. Observe polarity when replacing the 1.5-volt D cell and connect as indicated.

The D cell is held in place with spring clips which also act as battery contact
clips. The 9-volt battery contacts and connector are polarized. To remove the
9-volt battery, first withdraw battery with mated connector from the compart­ment. Then remove the connector.

5.4 Fuse Replacement

The 1 and 2 ampere fuse (also the 1A spare) is located in the externally acces­sible battery and fuse compartment. Access to the compartment is obtained by
disconnecting the test leads and loosening the single captivated screw on the
compartment cover. To replace or check a fuse: Apply pressure to the 1 amp fuse
cup then rotate the plate to expose a selected fuse for removal from the panel’s
cavity.

NOTE: When replacing fuses, it is important to use the same type and value as
the ones you have removed.

5.5 Test Lead Inspection

Periodic inspection of the test leads is recommended to detect cuts, burned ar­eas, deterioration or other damage that could reduce the insulation strength of
leads.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

28

5.6 Care

Immediately clean all spilled materials from the Instrument and wipe dry. If the
spillage is corrosive, use a suitable cleaner to neutralize the corrosive action.

Whenever the Instrument is not in use, rotate the function switch to the OFF posi­tion.

Whenever possible, avoid prolonged exposure or usage in areas which are sub­ject to temperature and humidity extremes, vibration or mechanical shock, dust or
corrosive fumes, or strong electrical or electromagnetic interferences.

Verify Instrument accuracy by performing operational checks using known, accu­rate, stable sources. If proper calibration equipment is not available, contact the
nearest Authorized Service Center. If the Instrument has not been used for 30
days, check the batteries for leakage and replace if necessary.

It is recommended that the Instrument be returned annually to the nearest Autho­rized Service Center, or to the factory, for an overall check, adjustment, and cali­bration.

When the Instrument is not in use, store it in a room free from temperature ex­tremes, dust, corrosive fumes, and mechanical vibration or shock. If storage time
is expected to exceed 30 days, remove batteries.

Find Quality Products Online at: [e-mail]

www.GlobalTestSupply.com

29