Safety 
This manual contains information and warnings that must 
be followed for operating the Instrument safely and 
maintaining the product in a safe operating condition. 
A 
CAUTION. 
Caution statements identify conditions or 
LIApractices 
that could result in damage to the 
equipment or other property. 
A 
WARNING. 
Warning statements identify conditions 
La or practices that could result in personal injury or 
loss of life. 
Terms as Marked on Equipment 
A
ATTENTION 
Refer to manual 
Do Not Operate Without Covers — 
To avoid personal 
injury, do not apply any voltage or current to the product 
without the covers in place. 
Electric Overload — 
Never apply a voltage to a connec-
tor on the product that is outside the range specified for 
that connector. 
Do Not Immerse — 
The product is not waterproof. 
Product Description 
The DMM155 and DMM157 are rugged, handheld digital 
multimeters that allow you to make accurate measure-
ments quickly and easily. Whether you are a professional 
or hobbyist, these instruments provide a useful range of 
features: 
• 
Shock-absorbing cover 
• 
Tilt stand, holster hook, and probe holders 
• 
33 digit (2000 count) LCD display 
• 
Auto range (volts, ohms) and manual selection 
• 
Measurement hold or offset 
• 
Measures DC and AC voltages, DC and AC current, 
resistance, diode voltage, continuity, and capacitance 
(DMM157) 
• 
Overvoltage and overload protection 
• 
Low-power ohms setting 
• 
Diode and continuity tester with audible signal 
• 
Alarm that warns of improper connections to the 
current inputs 
• 
Recessed input jacks for safety 
• 
Automatic power off after 30 minutes prolongs battery 
life 
• 
Low-battery indicator 
• 
Uses standard 9 V battery 
• 
Double Insulated 
II 
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