THE MULTITESTER

A multimeter or a multitester, also known as a VOM (volt-ohm-milliammeter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter can measure voltage, current, and resistance. Analog multimeters use a microammeter with a moving pointer to display readings.

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A. PARTS OF A MULTI TESTER

  • RANGE SELECTOR KNOB (Selector switch) makes it possible to select different functions and range of the meter. POINTER - The needle-shaped rod that moves over the scale of a meter. It is mechanically connected to the moving coil.

  • Adjustment screw - makes it possible to adjust the pointer to the zero position of the scale.

  • SCALE is a series of marking used for reading the value of a quantity.

  • Test probe positive (red), negative (black) - used to connect the circuit to the electrical components being tested.

  • Zero-ohm adjusting Knob is used to zero-in the pointer before measuring resistance.


B. Proper care and maintenance of the multi tester

  • Read manual of instructions on how to operate the multi-tester.

  • In reading the amount of voltage, always start with the highest range to avoid reading voltage higher than the tester setting.

  • Be sure that the tester is set to the correct range setting: resistance range when measuring the ohm, voltage range when measuring voltage and ammeter range when measuring the value of electric current.

  • Always check the condition of its battery. Worn out batteries will damage the internal setting of the tester.

  • When the tester is not in used or will be stored, set the selector switch to 1000V or to OFF position.

  • Never drop the tester.


How to read the meter scale of the multi tester

To read the resistance range of the multi-tester, the given table below will be used. The unit of measurement to be used to determine its resistance is ohm.

Voltage scale

Activity 3 Show that you learned something by doing this activity

I. USE MEASURING TOOLS

Supplies and Materials

  • Sheet of paper

  • Pencil

Tools and Equipment

  • Steel rule

  • Bench rule

  • Metric rule

  • Foot rule

Direction: Using any of the given measuring tools, read the actual measurement of the given samples. Write your answer on the space provided.

II. READING A VOLTMETER

Indicate the voltage reading of the voltmeter below

Directions: Write your answer on the space provided.

1._______ VOLTS

2._______ VOLTS

III. READING AN OHMMETER

A. Indicate the resistance reading of the ohmmeter below. Direction: WRITE YOUR READING AT THE SPACE PROVIDED.

1. ____________OHMS

2. ____________OHMS

3. ____________OHMS

4. ____________OHMS

Self Check 2.1