Mastech M266 Series User Manual

1. SAFETY INFORMATION
The meter is completely portable, LCD, 3 1/2 digit clamp meter with
insulation test function (with option 500V insulation tester unit). It has
been designed according to IEC1010-1 IEC1010-2-032 concerning
electronic measuring instruments with an overvoltage category (CAT II
1000V & CAT III 600V) and pollution 2 and safety requirements for hand-
held current clamps for electrical measurement and test.
Follow all safety and operating instructions to ensure that the meter is
used safely and is kept in good operating condition.
1.1
PRELIMINARY
When using this meter, the user must observe all normal safety
rules concerning:
Protection against the dangers of electronic current.
Protection of the meter against misuse.
Full compliance with safety standards can be guaranteed only if
used with test leads supplied. If necessary, they must be replaced
with the same model or same electronic ratings. Measuring leads
must be in good condition.
1.2
DURING USE
Never exceed the protection limit values indicated in
specifications for each range of measurement.
When the meter is linked to measurement circuit, do not touch
unused terminals.
When the value scale to be measured is unknown beforehand, set
the range selector at the highest position.
Before rotating the range selector to change function, disconnect
test leads from the circuit under test.
When carrying out measurements on TV or switching power
circuits always remember that there may be high amplitude
voltage pulses at test points, which can damage the meter.
Never perform resistance measurements on live circuits.
Always is careful when working with voltage above 60V dc or 30V
ac rms. Keep fingers behind the probe barriers while measuring.
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1.3
SYMBOLS
Important safety information, refer to the operating manual.
Dangerous voltage may be present.
Double insulation ( Protection class II ).
Application around and removal from HAZARDOUS LIVE
conductors is permitted.
Earth ground.
1.4
MAINTENANCE
Before opening the meter, always disconnect test leads from all
sources of electric current.
If any faults or abnormalities are observed, the meter can not be
used any more and it has to be checked out.
Never use the meter unless the back cover and the battery cover
are in place and fastened fully.
Do not use abrasives or solvents on the meter, use a damp cloth
and mild detergent only.
2. DESCRIPTION
This meter is one of a series portable 3 1/2 digital clamp meter for
measuring DC and AC Voltage, AC current, resistance, continuity test and
insulation test. Some models also provide frequency or temperature test.
Full overload protection. Low battery indication and over-range indication
are providing. Following table shows function of the series of clamp meter.
FUNCTION
M266
M266F
M266C
ACV DCV
※
※
※
ACA
※
※
※

※
※
※
※
※
※
※
INSULATION
※
※
※
TEMPERATURE
※
FREQUENCY
※
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Mastech M266 Series Specifications

General

Model	M266 Series
Category	Multimeter
Diode Test	Yes
Continuity Test	Yes
Measurement Functions	AC Current, AC Voltage, DC Voltage, Resistance, Continuity, Diode Test
DC Voltage Range	0-1000V
AC Voltage Range	0-750V
Battery	9V

Summary

Safety Information and Symbols

Preliminary Safety Rules

General safety rules to observe when using the meter.

During Use Safety Precautions

Safety measures to follow while operating the meter.

Meter Description and Controls

Function and Range Selector

Explains the rotary switch for selecting functions and ranges.

Transformer Jaws Operation

Details on how to use the transformer jaws for current measurement.

Data Hold Function

How to use the data hold switch.

Input Jacks Description

Information on the meter's input jacks.

Operating Instructions

Measuring Current

Step-by-step guide for measuring AC current.

Insulation Test

Procedure for performing insulation resistance tests.

Measuring Voltage

How to measure DC and AC voltage.

Measuring Resistance

Steps for measuring resistance.

Testing Diode

How to perform a diode test.

Continuity Test

Procedure for continuity testing.

Measuring Temperature

Instructions for temperature measurement.

Measuring Frequency

How to measure frequency.

Specifications and Accessories

General Specifications

Overall technical specifications of the clamp meter.

AC Current Specifications

Detailed specs for AC current measurement.

Insulation Test Specifications

Specifications for insulation testing.

AC Voltage Specifications

Technical details for AC voltage.

DC Voltage Specifications

Technical details for DC voltage.

Resistance Specifications

Specifications for resistance measurements.

Temperature Specifications

Specifications for temperature measurement (M266C only).

Frequency Specifications

Specifications for frequency measurement (M266F only).

Included Accessories

List of items that come with the clamp meter.

Battery Replacement