Simpson 260 Series 8 Instruction Manual

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

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 symbols 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.

This instrument is designed to prevent accidental shock to the operator when
properly used. However, no engineering design can render safe an instrument
which is used carelessly. Therefore, this manual must be read carefully and com­pletely before making any measurements. Failure to follow directions can result
in serious or fatal accident.

Shock Hazard: As defined in American National Standard, C39.5, Safety Re­quirements for Electrical and Electronic Measuring and Controlling Instrumenta­tion, a shock hazard shall be considered to exist at any part involving a potential
in excess of 30 volts RMS (sine wave) or 42.4 volts DC or peak and where a
leakage current from that part to ground exceeds 0.5 milliampere, when mea­sured with an appropriate measuring instrument defined in Section 11.6.1 of
ANSI C 39.5.

Technical Assistance

SIMPSON ELECTRIC COMPANY offers assistance Monday through Friday
7:30 am to 5:00 pm Central Time by contacting Technical Support or
Customer Service at [phone].
Internet: http://www.simpsonelectric.com

Warranty and Returns

SIMPSON ELECTRIC COMPANY warrants each instrument and other ar ticles
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 author ized 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.

®

260

is a Registered Trademark of the Simpson Electric Co.

2

NOTES

3

Contents

1. INTRODUCTION ................................................................................. 7

1.1 General Description ........................................................................... 7

1.2 Overload Protection ............................................................................ 7

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

1.4 Printed Circuit ..................................................................................... 8

1.5 Phenolic Case .................................................................................... 8

1.6 Adjust-A-Vue Handle .......................................................................... 8

1.7 Test Leads .......................................................................................... 8

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

1.9 Definition of Accuracy....................................................................... 1 0

1.10 Safety Considerations ...................................................................... 10

1.11 Accessory AC High Voltage Probe ................................................... 1 1

1.12 Amp-clamp Model 150-2 .................................................................. 1 1

2. INST ALLATION ................................................................................. 11

2.1 Unpacking and Inspection ............................................................... 11

2.2 Warranty ...........................................................................................11

2.3 Power Source Requirements ........................................................... 12

2.4 Operating Position ............................................................................ 1 2

3. CONTR OLS, JA CKS AND INDICATORS........................................... 1 2

3.1 Front Panel Description .................................................................... 12

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

4.1 Safety Precautions ........................................................................... 14

4.2 Polarity Reversing ............................................................................ 15

4.3 Measurement of Unknown Voltage or Current ................................. 1 5

4.4 Test Leads ........................................................................................ 1 5

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

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

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

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

4.9 DC Voltage Measurement 0-1000V Range ..................................... 1 8

4.10 AC Voltage Measurement 0-2.5 ~ 0-250V Range ...........................18

4.11 AC Voltage Measurement 0-500V Range ........................................ 1 9

4.12 AC Voltage Measurement 0-1000V Range .....................................20

4.13 Output Voltage Measurement ...........................................................21

4.14 Decibel Measurement (–20 to +50 dB) ........................................... 2 2

4.15 Direct Current Measurement ............................................................ 2 3

4.15.1 Direct Current Measurement 0-50µA Range ................................... 23

4.15.2 Direct Current Measurement 0-1mA through 0-500mA Range ...... 24

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

4.16 Resistance Measurements ............................................................... 25

4.16.1 Measuring Resistance ...................................................................... 25

4.16.2 Resistance Measurement of Semiconductors ................................. 26

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

5.1 Inspection .........................................................................................27

5.2 Battery Replacement ........................................................................ 2 7

5.3 Fuse Replacement ........................................................................... 28

5.4 Test Lead Inspection ........................................................................28

5.5 Care ..................................................................................................28

4

NOTES

5

NOTES

6

1. INTRODUCTION

1.1 General Description

The Simpson Volt-Ohm-Milliammeter 260 Ser ies 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 multipurpose 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. F or 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 5.3 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 r ange is not fused. The shunt connects directly to the –10A and
+10A jacks.

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

1.3 Internal Batteries

There are two batteries in the ohmmeter circuits, a NEDA 13F size D cell that
furnishes 1.5-volts for the R X 1 and R X 100 ranges and a NEDA 1604 battery
that 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.

7

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 has heavy reinforced walls for maximum durability and pro­vides excellent protection for the circuit components. Batteries and fuses can be
accessed 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 Handle

A carrying handle is attached to the Instrument case. The handle ma y 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 provides 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.

NOTE: These ratings for the test leads must not be exceeded in any application.

1.8 Technical Data

TABLE 1-1. Technical Data for the 260-8

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 V OLTS:
Ranges: 0-2.5-10-25-50-250-500-1000V
Sensitivity: 5,000 ohms per volt

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

8

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

6. DC MILLIAMPERES:
Ranges: 0-1-10-100-500 mA
V oltage 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.

ECNATSISER1XR001XR000,01XR

egnaR000,2-0 ⍀ 000,002-0 ⍀ M02-0 ⍀

gnidaeRretneC21 ⍀ 0021 ⍀ 000,021 ⍀

tiucriCnepOlanimoN

egatloV

tiucriCtrohSlanimoN

tnerruC

V5.1V5.1V9

Am521Am52.1Aµ57

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.
** Responds to the average value of an AC current, and is calibrated to indicate
the RMS value of a pure sine wave

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

600⍀ line.

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

12. FUSE: F1 1A, 250V , type 3A G, quick acting 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: 5-1/2” x 7" x 3-1/8 ” (13.34 x 17.78 x 7.94 cm)

9

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 symbols throughout the publication, where applicable, and is
defined on the inside front cover of the manual under NOTES AND SAFETY
INFORMATION. Adhere to these instructions in order to ensure the safety of
operating and servicing personnel and to retain the operating conditions of the
Instrument.

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

Quantity Description Catalog No.

1 Test Lead Set – one red and one black

((48” long) each with combination probe tip

and removable rubber-sleeved alligator clip. 00043
*1 1.5 Volt, D Cell, NEDA 13F
*1 9.0 Volt Cell, NEDA 1604
2 1 Amp, 250V Fuse, Littlefuse T ype #312001
1 2A, 600V Fuse, Littlefuse Type BLS or

(Bussman Type BBS)
1 Operator’s Manual 6-114338

* Batteries are standard items, replaceable from retail stores.

TABLE 1-3. Additional Accessories

Description Catalog Number

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

Leatherette Ever-Redy Hard Case, Drop Front ................................... 00805

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

Model 151-2 Line Splitter..................................................................... 00544

10

1.11 Accessory AC High Voltage Probe

The 10,000 V AC high voltage probe extends 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.

1.12 Amp-clamp Model 150-2

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

2. INSTALLATION

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.

2.1 Unpacking and Inspection

Examine the shipping carton for signs of damage. If damaged, notify the carrier
and supplier and do not attempt to use 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 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 5 for instruc­tions on how to install the batteries.)

2.2 Warranty

The Simpson Electric Company warranty policy is printed on the inside front
cover of this manual. Read it carefully before requesting any warranty repairs. For
all assistance, including help with the Instrument under warranty, contact the
nearest Authorized Service Center. If necessary, 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.

11

2.3 Power Source Requirements

There are two batteries in the ohmmeter circuits, a NEDA 13F D size cell that
furnishes 1.5 volts for the R X 1 and R X 100 ranges and a NEDA 1604 battery that
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.)

2.4 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 promises greater accuracy since the Instrument is calibrated
in this position.

3. CONTROLS, JACKS AND INDICATORS

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 before oper­ating the Instrument.

3.1 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 4-1/4” indicating Instrument. Below the In­strument are four controls and eight circuit jacks.

2. Range Switch: This switch may be rotated in either direction to

select 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 function switch at the –DC or +DC
position, depending on the polarity of the input sig­nal. To measure A C voltage set the function switch
to the AC position. 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.

12

O

H

M

OHMS

.C.

D

A.C.

2.5 V.A.C.

1

DB

S

D

.C

.

A

.C

.

6

-10 A.

OUTPUT

350 VDC

A.C. VOLTS

ONLY

- D.C.

+ D.C.

3

COMMON

500 MA.

MAX.

2.5 V.
10 V.

1V.

25 V.
50 A.

␮

OFF

AMPS.

250 V.

500 V.
I000 V.

+

-

ALL TERMINALS 1 V MAX

100MA.

10MA.
1MA.

R X I00

R x I0,000

260

5

+10A

+1V.

50 ␮ AMPS.
+

250 MV.

ZERO OHMS

AMPS.

R x 1

500 V.

1000 V.

A.C. D.C.

A.C. D.C.

4

2

Figure 3-1. Front Panel Controls, Jacks and Indicators

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 4 for details.)

6. P ointer Adjust For Zero: This control is used to mechanically z ero 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 that the pointer rests freely over the zero mark.

13

4. OPERATION

!

Multifunction 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, etc. 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.

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

4.1 Safety Precautions

The following precautions are suggestions of commonly recognized safe prac­tices to adopt and specific hazards to be avoided and are not implied to be
sufficient to safeguard 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 who are 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. Before 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

capable of giving aid is alert and located nearby.
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

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

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

personal injury.

14

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 on is properly grounded and

fuses are the proper type and rating.
l. Double check switch positions and jack connections before applying power

to the Instrument.
m. 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 VOMs designed for this purpose.

4.2 Polarity Re ver sing

The function switch conveniently reverses 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.

4.3 Measurement of Unknown Voltage or Current

The approximate voltage or current to be measured is sometimes known and the
correct range can easily be selected. However, particularly when working upon
faulty equipment, the voltage or current can either be unknown or higher than
normal or anticipated. When 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.

4.4 Test Leads

Test leads are provided with accessor y screw-on alligator clips which may be
attached to the probe tips. Eliminating the need to hand-hold test prods to a
circuit for extended periods, the test clips also reduce 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.

1515

4.5 DC Voltage Measurement 0-250mV Range

!

Before making voltage measurements, re vie w the SAFETY PRECAUTIONS listed
in paragraph 4.1. Also, when using the 260 as a millivoltmeter, care must be
taken to prevent damage to the indicating instrument from excessive voltage.
Before using the 250 millivolt range, use the 1.0-volt DC range to determine that
the voltage measured 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 into 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 4.2.

4.6 DC Voltage Measurement 0-1V Range

a. Set the function switch at +DC (Fig-

ure 4-1).
b. Plug the black test lead into the –

COMMON jack and the red test

lead into the +1V jack.

.

.C

D

D

.C

.

c. Set the range switch at 1V (com-

mon position with 10V).
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 fig-

- D.C.

+ D.C.

COMMON

ures marked 0-10. Then divide the

reading by 10.

Figure 4-1. Jacks and Switch Positions
for Measuring DC Voltages, 0 through
250V Ranges

NOTE: For polarity reversing see paragraph 4.2.

16

+10A

+1V.

50 ␮ AMPS.
+

2.5 V.
10 V.

1V.

25 V.
50 A.

␮ AMPS.

250 V.

500 V.
I000 V.

+

-

260

ALL TERMINALS 1 V MAX

250 MV.

4.7 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 r anges, 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.

4.8 DC Voltage Measurement 0-500V Range

!

Use extreme care 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
paragraph 4.1.

a. Set the function switch at +DC (Fig-

ure 4-2).
b. Set the range switch at the 250V/

500V/1000V position.
c. Plug the black test lead into the –

COMMON jack and the red test lead

into the 500V jack.
d. Be sure power is off in the circuit be-

ing measured and all capacitors dis-

charged. Connect the black test lead

to the negative side of the circuit be-

ing measured and the red test lead

to the positive side of the circuit.
e. Turn on power in circuit being mea-

sured.
f. Read the voltage using the 0-50 fig-

ures on the black scale marked DC.

Multiply the reading by 10.
NOTE: Tur n off power to the circuit and

wait until the meter indicates zero before
disconnecting the test leads.

D.C.

- D.C.

+ D.C.

COMMON

250 V.

500 V.
I000 V.

-

260

ALL TERMINALS 1 V MAX

500 V.

A.C. D.C.

Figure 4-2. Jacks and Switch
Positions for Measuring DC Voltage,
0-500V Range

D.C.

17

4.9 DC Voltage Measurement 0-1000V Range

!

Use extreme care 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
paragraph 4.1.

a. Set the function switch at +DC (Fig-

ure 4-3).
b. Set the range switch at the 250V/

500V/1000V position.
c. Plug the black test lead into the –

COMMON 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 cir-

cuit being measured and the red

test lead to the positive side of the

circuit.
e. Turn on power in circuit being mea-

sured.
f. Read the voltage using the 0-10 fig-

ures on the black scale marked DC.

Multiply the reading by 100.
NOTE: Turn off power to the circuit and

wait until the meter indicates zero

before disconnecting the test leads.

.

.C

D

- D.C.

+ D.C.

COMMON

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

D

.C

1000 V.

A.C. D.C.

.

4.10 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 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).

18

Before proceeding with the following steps, review the Safety Precautions in
Paragraph 4.1.

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 ac-

tual voltage present, always

use the highest voltage range

as a protection to the Instru-

ment. If the voltage is within a

PERCENT RELATIVE ERROR

+5
+4

+3

+2

+1

0

-1

-2

-3

-4

-5

AC VOLT A GE RANGES

2.5 VAC RANGE
10 VAC RANGE
25 VAC RANGE
50 VAC RANGE

250 VAC RANGE
500 VAC RANGE

1000 VAC RANGE

lower range, the switch may be

10Hz

set for the lower range to ob­tain a more accurate reading.)

c. Plug the black test lead into the

– COMMON jack and the red

100Hz 1KHz 10KHz

FREQUENCY

100KHz

FIGURE 4-4. Frequency Response,
AC Voltage Ranges

1MHz

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.

A.C.

2.5 V.A.C.

A.C.

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.

A.C . VO LTS

ONLY

COMMON

2.5 V.
10 V.

1V.

25 V.
50 A.

␮ AMPS.

250 V.

500 V.
I000 V.

+

-

260

ALL TERMINALS 1 V MAX

4.11 AC Voltage Measurement 0-500V Range

Use extreme care 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 4.1 and in the instruction
manual for the equipment being tested.

Figure 4-5. Jacks and Switch Positions
for Measuring AC Voltage 0-2.5 through
0-250V Ranges

19

!

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 4.1.

a. Set the function switch to AC

Volts Only position (Figure 4-6).

!

.

.C

NOTE: 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 capacitors 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.

4.12 AC Voltage Measurement 0-1000V Range

Use extreme care 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 4.1 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 V olts Only position, and test leads connected to common and 1000V

A

A.C . VO LTS

ONLY

COMMON

2.5 V.
10 V.

1V.

25 V.
50 A.

␮ AMPS.

250 V.

500 V.
I000 V.

-

260

ALL TERMINALS 1 V MAX

500 V.

A.C. D.C.

FIGURE 4-6. Jacks and Switch
Positions for Measuring AC Voltage
0-2.5 Through 0-250V Ranges

5

0

A.C.

ZERO OHMS

20

jack. Do not touch the Instrument or test leads while the power is on in the circuit
being measured.
Before proceeding with the fol­lowing steps, review the Safety
Precautions in Paragraph 4.1.
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

.

.C

A

10

A

.C

.

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 capacitors

have been discharged.
e. Connect the test leads

across the circuit voltage to

be measured with the black

lead to the grounded side.
f. T urn on the pow er in the cir-

cuit being measured.

A.C. VOL TS

ONLY

COMMON

2.5 V.
10 V.

1V.

25 V.
50 A.

␮ AMPS.

250 V.

500 V.
I000 V.

-

260

ALL TERMINALS 1 V MAX

500 V.

A.C. D.C.

ZERO OHMS

g. Read the voltage on the red

scale marked AC. Use the

0-10 figures and multiply by 100.

FIGURE 4-7. Jacks and Switch Positions
for Measuring AC Voltage 0 Through
1000V Range

4.13 Output V oltage Measurement

It’s often necessary 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.

Figure 4-8. Frequency

Response Output Ranges

+10

+8

+6

+4

+2

0

-2

-4

-6

-8

-10

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

OUTPUT RANGES

2.5 VAC RANGE
10VAC RANGE

25/50 VAC RANGE

250 VAC RANGE

FREQUENCY

21

Before proceeding with the fol­lowing steps, review the Safety
Precautions in Paragraph 4.1.

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

.C.

A

A.C

.

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. T urn on the power in the test

circuit. Read the output volt­age on the appropriate AC

A.C. VOL TS

ONLY

COMMON

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

voltage scale. For the 0-

2.5V range, read the value
directly on the scale marked

2.5 VAC. For the 10V, 25V,

Figure 4-9. Jacks and Switch Positions for
Output Measurements

50V, or 250V ranges, use the red scale marked AC and read the black figures
immediately above the scale.

4.14 Decibel Measurement (–20 to +50 dB)

Some industries measure 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 23.

a. Review the safety precau-

tions in paragraph 4.1.

b. Refer to Figure 4-10 for

switch settings and jack
connections.

Figure 4-10. Jacks and Switch
Positions for Measuring
Decibels.

22

A.C. VOL TS

ONLY

COMMON

.

.C

A

2.5 V.A.C.

OUTPUT

350 VDC

500 MA.

MAX.

2.5 V.
10 V.

1V.

25 V.
50 A.

␮ AMPS.

250 V.

500 V.

-

I000 V.

ALL TERMINALS 1 V MAX

A.C

.

260

c. Use operating instructions for AC VOLTAGE MEASUREMENT, 0-2.5/10/25/

50/250V RANGES (paragraph 4.10).
NOTE: 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:

egnaRegatloVegnaRBdgnidaeR

V5.2-001+ot02-yltceriddaer
V01-022+ot8-gnidaerotBd21+dda
V52-003ot0gnidaerotBd02+dda
V05-063+ot6+gnidaerotBd62dda

V052-005+ot02+gnidaerotBd04dda

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

4.15 Direct Current Measurement

!

a. Do not change the range setting of the range or function switches while the

circuit is energized.

b. Never disconnect test leads from the circuit under measurement while it is

energized.

!

c. Always turn the power off and discharge all the capacitors before the setting

of the switches is changed, or the leads disconnected.

d. Never exceed the circuit-to-ground voltage of the instrument (1000 v max.,

table 1-1, item 16).
d. Always connect the instrument in series with the grounded side of the circuit.
e. 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.

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

in microamperes.

NOTE: For polarity reversing see paragraph 4.2.

2323

4.15.2 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. Tur n the power on. Read

the current in milliamperes
on the black DC scale. For
the 1 mA range, use the 0­10 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 dis-

connect the test leads.

.

.C

D

-10 A.

OUTPUT

350 VDC

A.C. VOL TS

- D.C.

+ D.C.

ONLY

OFF

COMMON

-

MAX.

+

500 MA.

50 A.

␮ AMPS.

ALL TERMINALS 1 V MAX

100MA.

10MA.
1MA.

260

Figure 4-11. Jacks and Switch Positions for
Measuring Direct Current

D

.C.

+10A

+1V.

50 ␮ AMPS.

+

AMPS.

250 MV.

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.

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

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

0-10 figures to read directly in amperes.

!

24

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

!

NOTE: 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 damage the test jacks or leads
and the arcing may be hazardous to the operator. Tu rn 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 0­10A 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.

4.16 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 5.)

e. Disconnect shorted test leads.

4.16.1 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

(Figure 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 unless there are semiconductors in the circuit. (See para­graph 4.16.2.) Adjust ZERO OHMS control for each resistance range.

25

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 re-

sistance value, multiply the
reading by the factor at the
switch position. (K on the
OHMS scale equals one
thousand.)

OHMS

O

H

M

S

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

+ D.C.

- D.C.

COMMON

-

+

ALL TERMINALS 1 V MAX

R x 1

R X I00

R x I0,000

260

4.16.2 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

5. OPERATOR MAINTENANCE

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

5.1 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.
If the battery compartment cover is removed for any reason, check that the proper

fuses are being used.

5.2 Battery Replacement

Figure 5-1. Battery and Fuse Compartment

a. Two batteries supply power for resistance measurements, a 1.5-volt D cell

and a 9-volt battery . When it is no longer possib le to adjust the pointer to zero
for the R X 1 and R X 100 ranges (refer to ZERO OHMS ADJUSTMENT
paragraph 4.16), 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.

27

NOTE: Batteries should be replaced before their useful lif e has e xpired. 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-v olt 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.

5.3 Fuse Replacement

The 1 and 2 ampere fuse (also the 1A spare) is located in the externally acces­sible battery and fuse compartment. Access compartment 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.

5.4 T est 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.

5.5 Care

a. 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.

b. When the Instrument is not in use, rotate the function switch to the OFF

position.

c. Avoid prolonged exposure or usage in areas which are subject to tempera-

ture and humidity extremes, vibration or mechanical shock, dust or corrosive
fumes, or strong electrical or electromagnetic interferences.

d. 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 Instr ument has not
been used for 30 days, check the batteries for leakage and replace if neces­sary.

e. 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.

f. When not in use, store the Instrument in a room free from temperature ex-

tremes, dust, corrosive fumes, and mechanical vibration or shock. If storage
time is expected to exceed 30 days, remove batteries.

28

NOTES

29

NOTES

30

NOTES

31

SIMPSON ELECTRIC COMPANY 853 Dundee Avenue

Elgin, IL 60120-3090 [phone] FAX [phone]

Printed in U.S.A. Part No. 06-114338 Edition 10, 1/02

Visit us on the web at: www.simpsonelectr ic.com

32