Reading Analogue Multimeter

Reading the analogue multimeter is a necessary skill for aircraft engineer. Unfortunately the EASA syllabus is arranged in such a way that the learning about multimeter is covered in module 7. However students are expected to be able to use the meter as the earlier modules, such as module 3 and 4 require the use of meter for testings. Example module 3. 9, test of capacitor and module 4. 1, the test for diode.

I had located the site to learn about multimeter. Please follow the link to:
http://www.tequipment.net/pdf/velleman/velleman_avm360_manual.pdf

The area of knowledge to be covered in the use of the meter.
Although it is not stated that the students need to know the working of the meter, I do cover it in order to bring the understanding of the usage of the meter.
a. Construction of the meter.
b. The changes and connections needed to make it reads current, voltage and resistance.
c. The names of the different parts and scales.
d. How to use it to read DC voltage and Current, AC voltage and resistance.
e. The different between Digital and analogue meter.

Take note: for ampere and voltage readings, 0 is on the left and maximum is on the right. However for resistance (ohms) , 0 is on the right and maximum is on the left. Why?. As a student of aircraft maintenance license, you should be able to explain why.

There are three connecting terminals. Many students are wondering about output terminal. The purpose is to measure AC Voltage, when the AV voltage is superimposed on DC.

Module 7 Electrical Subjects

If you are going for B1.1 license, there are three big module for you to do. They are:
- module 7         - Maintenance Practices
- module 11A    - Aerodynamics, Structure and System
- Module 15      - Turbine engine

To facilitate in the delivery of the lectures, we had divided the module 7 into 4 submodules, one of which is on the electrical subject. It covers the following subjects:
- Topic 7.1 -    electrical safety
- Topic 7.4 -    General Test Equipment
- Topic 7.5 -    Schematic and Wiring Diagram
- Topic 7.7    - EWIS
- Topic 7.15 - Soldering

Basic Usage of Multimeter Module 7

The usage of various common measuring instrument is included in the syllabus. The most commonly used are:

- multimeter
- insulation tester
- bonding tester.

This post is about multimeter. From its name, you can expect that the meter it to measure a number of functions. The most common are:
- AC Voltage
- DC Voltage
- DC Current
- Resistances

There are a number of skills set you need to have to use the meter effectively. There are:
- meter construction theory
- basic electric circuit theory.
- safety practices
- practical skills.

A: Meter construction theory. You can still be able to use the meter effectively even if you do not have any theoritical background knowledge. However you will have a number of disadvantages, for example, you are likely unable to know if the meter is in good operating condition or not.

Basically all meters, in its basic form are ammeters. That means it is operated by current. The way the circuits are wired will determine if it is voltmeter, ammeter or ohmmeter.

B: The basic circuit theory: It is required to assist you in deciding on how to connect the meter. To read the voltage, you have to choose two points to measure the potential different. Thus the voltmeter connection is in parallel. To read current, the meter has to be connect in series with the load.

To read the resistance, the resistor has to be isolated, otherwise the reading will not be accurate.

C: Safety practices: Current can cause death and injury. This mean, you have to know how to work with electricity. Unless you know for certain, assume that the wire or connections have fatal voltage. A voltage as low as 50 volt can cause injury. Avoid wearing conductive rings or watches, as these items can be in contact with life wire.

D: Practical Skills will enable you to handle the equipment and wiring.

Enclosed is a video on how to use a multimeter.