Sealey MM20 - Manual

Heavy duty general purpose multimeter with clear and easy to read LCD display. Features data hold function,
temperature probe and diode test facility. Housed in rugged rubber boot with integral stand. Supplied with full
set of leads and probes.
 WARNING! Ensure that you read, understand and apply the safety and operational instructions
before connecting the multimeter. Only when the user is sure that they understand the procedures, is it safe to proceed with testing.
Normal operating: temperature range: 0 °C to 40°C, relative humidity less than 75%.
Remember to turn off the multimeter when measurements are completed.
NOTE: WHEN THE FIGURE '1' IS DISPLAYED, IT INDICATES AN OVER-RANGE SITUATION AND A HIGHER RANGE NEEDS TO BE SELECTED.
3.1. MEASURING VOLTAGE (AC AND DC)
3.1.1. Connect the black test lead to the COM input socket and the red test lead to the VΩmA input socket.
3.1.2. Set the rotary switch to the required V (DC) or V ~ (AC) range, if unsure of the voltage range to be tested, set switch to the highest range first and then
lower it until a satisfactory reading is obtained.
3.1.3. Connect the test probes across the source or load under measurement.
3.1.4. Turn on the power, the voltage will be displayed and the polarity of the red test lead connection will be indicated when measuring DC voltages.
3.2. MEASURING CURRENT (DC ONLY)
3.2.1. Connect the black test lead to the COM input socket and the red test lead to the VΩmA input socket, or for measuring in the 200mA to 10A range, use the 10A
DC input socket.
3.2.2. Set the rotary switch to the required A (DC) range and connect the test probes in series with the load under measurement.
3.2.3. The current measured will be displayed.
1.1. PERSONAL PRECAUTIONS
 When using this multimeter, please observe all normal safety rules concerning:
Protection against the dangers of electrical current.
Protection of the meter against misuse.
 Full compliance with safety standards can only be guaranteed if used with the test leads supplied. If necessary, they must be replaced with genuine Sealey
leads with the same electronic ratings. Failure to do so will invalidate the warranty.
 DO NOT use leads if damaged or if the wire is bared in any way.
1.2. GENERAL SAFETY INSTRUCTIONS
 Familiarise yourself with the application and limitations of the multimeter as well as the potential hazards. IF IN ANY DOUBT CONSULT A QUALIFIED
ELECTRICIAN.

Before commencing testing, follow instructions below and select the correct input sockets, function and range on the multimeter.
 When the meter is connected to a circuit, do not touch any unused meter terminals.
 When the magnitude of the value to be measured is unknown beforehand, set the range selector to the highest value available.
 Before rotating the range selector to change functions, disconnect test probes from the circuit under test.
 WARNING! Never perform resistance, transistor, diode or continuity measurements on live circuits.
 Always take care when working with voltages above 35V DC or 25V AC rms. These voltages are considered a shock hazard.
 WARNING! USE EXTREME CAUTION when working with high voltages.
 Always keep fingers behind the probe barriers whilst measuring and DO NOT use when hands are wet..
 Before attempting to insert transistors for testing, ensure that the test leads have been disconnected.
 Components should not be connected to the transistor socket when taking voltage measurements with the test leads.
 DO NOT test voltages above 600V AC or DC - the circuitry of the multimeter will be destroyed.
 WARNING! NEVER connect the multimeter to a voltage source / live circuit when the rotary switch is set to any other function apart from Voltage testing.
 ALWAYS discharge filter capacitors in power supplies and disconnect the power when making resistance or diode tests.
 WARNING! Voltage checks on electrical outlets can be difficult and misleading because of the uncertainty of connection to the recessed electrical contacts.
Other means should be used to ensure that the terminals are not “live”.
 DO NOT use the multimeter in a potentially explosive atmosphere or where flammable material is present.
 ONLY operate the multimeter when the back cover is in place and fastened securely.
 If any abnormal readings are observed, the multimeter must be checked out by an authorised technician.
 ALWAYS turn off the multimeter and disconnect the test leads, before opening the back cover to replace the fuse or battery.
 When not in use, store the multimeter carefully in a safe, dry, childproof location out of direct sunlight. If storing for a long period of time, remove the battery.
Storage temperature range: -15°C to 50°C.

Note: The warnings, cautions and instructions referred to in this manual cannot cover all possible conditions and situations that may occur. It must be understood
that common sense and caution are factors which cannot be built into this product, but must be applied by the operator.
INSTRUCTIONS FOR:
8 FUNCTION MULTIMETER WITH
THERMOCOUPLE
MODEL No:
MM20.V3
1. SAFETY
2. FEATURES
3. OPERATION
Layout:
1. 12.5mm LCD Display
2. Rotary Function Switch
3. VΩmA Input Socket
4. COM Input Socket
5. 10A Input Socket
6. Hold Button
7. Transistor Socket
Measures:
• AC Voltage
• DC Voltage
• DC Current
• Resistance
• Temperature
• Diode Test
• Continuity Test
• Transistor Test
1
2
3
7
6
5
4
Function Red Lead Connection Input Limits
V VΩmA 600V DC
V~ VΩmA 600V AC (sine)
A VΩmA 200mA DC
A 10A 10A DC 10A DC
h
FE
VΩmA 0-1000
°C VΩmA -40°C to 1000°C
VΩmA 70Ω
2k VΩmA 2kΩ
Ω VΩmA 2MΩ
MM20.V3 Issue No: 4 (S) - 12/05/15
I MPORTANT: PLEASE READ THESE INSTRUCTIONS CAREFULLY. NOTE THE SAFE OPERATIONAL REQUIREMENTS, WARNINGS & CAUTIONS.
USE THE PRODUCT CORRECTLY AND WITH CARE FOR THE PURPOSE FOR WHICH IT IS INTENDED. FAILURE TO DO SO MAY CAUSE DAMAGE
AND/OR PERSONAL INJURY AND WILL INVALIDATE THE WARRANTY. KEEP THESE INSTRUCTIONS SAFE FOR FUTURE USE.
Thank you for purchasing a Sealey product. Manufactured to a high standard, this product will, if used according to these instructions, and properly
maintained, give you years of trouble free performance.
The user shall ensure that test probes are correctly selected in order to prevent danger. Probes shall be selected to ensure that adequate barriers guard against
inadvertent hand contact with live conductors under test and that probes have minimal exposed probe tips. Where there is a risk of the probe tip short circuiting
with other live conductors under test, it is recommended that the exposed tip length shall not exceed 4mm.
Original Language Version © Jack Sealey Limited