There is a measuring device that combines the functions of several similar devices. It's called a multimeter. How to use it will be discussed in this article. It is mainly designed to measure mains voltage, resistance and electric current.
New Features
Manufacturers add new features to modern modifications of these devices:
- diode ringing;
- capacitor capacitance measurement;
- temperature measurement;
- Checking the operating parameters of transistors;
- measuring current frequency;
- sound probe.
Due to the fact that they have been added to existing functions, many users have a question: how to use a multimeter?
Classification of equipment in question
All modern multimeters can be divided into:
- Digital, which are the most popular because they are relatively inexpensive, perform many functions, and are easy to use.
- Pointer, in which readings are taken on a scale with an arrow. They have a small error due to the difference in this scale. However, the device is universal, capable of replacing ampere-, ohm- and voltmeters.
In the future, we will mainly consider how to use a digital multimeter, and at the end of the article we will return to its arrow version with some inserts along it along the way.
Checking resistance
Before this work, the multimeter must be prepared for it. The device has a toggle switch that switches to the position corresponding to the minimum measurement of the obtained value of the desired value. Such a measurement should be carried out with a complete de-energization of the circuits. To do this, the equipment whose resistance will be measured is disconnected from the mains, or batteries such as batteries are removed from there.
How to use a multimeter? The instructions provide that the performance of this device should be checked by connecting the ends of the corresponding probes. The device should show "0" either on the electronic display or using a magnetic needle. If this does not happen, then it is necessary to carry out the adjustment using the “Set. 0". All other cases require battery replacement.
Measuring DC voltage
Let's see how to usedigital multimeter when determining this indicator. Usually the sector responsible for this measurement is divided into 5 ranges:
- 200 mV;
- 2000 mV;
- 20 V;
- 200V;
- 2000 V.
However, their number may vary and include other limit values. This shows the maximum voltage that can be measured in this range. Probes intended for measurements are inserted as follows: black (common or negative) is inserted into the lower hole located on the right, and red (positive) into the one that is slightly higher.
In order to measure the battery voltage of 1.5 V, set the switch to position 20. With the corresponding measuring probes, touch the opposite poles of the battery and look at the screen, while the number 1, 49 should appear on it.
If the measured voltage is unknown, then you need to start from the largest range - 1000 V, so as not to burn the device, gradually reducing it until the required value is found. The fact that there is no voltage in this range will be indicated by zeros on the display. If there are zeros in front, but some number already appears, you can transfer the device to a position that is a multiple of the number of leading zeros compared to the one occupied in which this number was fixed. This is necessary if more accurate data is needed. If strong accuracy is not required, then you can take readings at the stage with zerosup to a significant number. Sometimes the multimeter does not burn out when setting a smaller range than the measured value, but shows "1". However, this state should not be allowed to happen too often.
We looked at how to use a multimeter correctly. If you accidentally confuse the negative and positive probes, nothing bad will happen, just the number displayed on the display will be with a “-” sign. Small ranges are used when working with amateur radio circuits and transistors.
Measuring AC voltage
It doesn't matter here where the plus and minus are on the probes. The work is carried out with high voltages, therefore it is impossible to touch the non-insulated parts of the probe during measurements.
This sector is divided into two:
- 200V;
- 750 V.
Measurement probes are placed in the multimeter in the same way as they were inserted when measuring direct voltage. To measure the indicator in question in the outlet, you need to set the range to 750, since 220 V is greater than 200. After finishing work, turn the device to the “Off” position.
Checking network integrity
To do this, you need to ring the last one. In order to perform this operation, a device with a magnetic needle deviating from “0” or with a dead battery can be used. Consider how to use a multimeter in this case.
The arrow should respond to the connection of the ends of the probes. Digital instruments should show a value close to zero, which maydiffer due to transient current resistance from the ends of the probes. When they are opened, the arrow is set to the infinity point on the corresponding devices, and on the digital ones, a reboot will begin or “1” will appear. If the ends of the probe are leaned against a direct conductor, then a zero value should appear.
If there is a built-in circuit ringing function, it should be carried out with respect to wires and low-resistance working circuits by setting the toggle switch to this position. In this case, a signal will be given, making the scoreboard unnecessary. In the event of a network break, there will be no sound, and the device will show near-zero values. This example shows how to use the DT-832 multimeter.
Using the meter as an ammeter
In order to determine the current strength, the device is connected to an electrical circuit. If there are bare wires, then the toggle switches of the device are turned off, the check is carried out with a special probe. In an active circuit, the current strength must be equal to 0. The place where measurements are made must be dry. Before working on your hands, it is better to wear gloves.
Checking the capacitor
He passes alternating current through himself. To carry out a capacitance check, the condition must be met that for the device it must be 0.25 μFarad, that is, the minimum.
When performing a check, the following actions are performed:
- identify the positive and negative poles of the capacitor;
- remove static electricity from him;
- multimetertransferred to the position of ringing or determining resistance;
- the probes of this device are touched to the terminals of the capacitor.
The most convenient in this case is to use an analog (pointer) multimeter, since it controls the movement of the arrow. The capacitor is working if the device squeaked or showed zero resistance. The displayed unit indicates that there is an open inside the capacitor.
Switch multimeter
How to use a dial multimeter? Basically, exactly the same, only the readings are not taken electronically from a digital display, but are read on a scale, along a frozen arrow. Manufacturers have released a combined pointer-digital device. With it, you can determine AC and DC current, resistance and capacitance of capacitors, test diodes, ring connections and check batteries.
According to user reviews, this type of multimeter is considered to be a poorer analogue compared to a digital device. This is due to the fact that the arrow may stick, the accuracy of the device is lower compared to digital. It is advised to use it when it is necessary to take measurements at two points simultaneously in conjunction with a digital multimeter when tracking their mutual dynamics.
Using the device in cars
How to use a multimeter in a car? In this case, the most popular functions are ringing and a voltmeter. Mostcommon is the DT-832 multimeter. How to use it, we will consider further.
The number 832 indicates that the device is equipped with a sound indication. It must be operated within the temperature range of 0-40 °C. Operates on batteries type "Krona". With it, you can measure the strength of direct current up to 10 A, alternating voltage - up to 750 V, direct - up to 1000 V, resistance - up to 2000 kOhm, the he alth of transistors and diodes.
A black probe is inserted into the “COM” socket, the two above are for the red variety. The current strength can be determined by the additional equipment for the car. In a 220 V network, this indicator cannot be measured.
You should choose a car multimeter based on the following provisions:
- better if the model is equipped with a sound alert;
- you need to choose one that has a fuse that can be replaced in the event of an erroneous action taken by the user;
- body should be rubberized.
In addition to the considered multimeter, other similar devices can be used in cars. The most compact, having small dimensions, coinciding with two matchboxes, is the DT-182 multimeter. How to use it? Similar. It is designed to measure resistance, voltage and current. You can also test transistors, diodes and batteries with it, ring the connections. This device is powered by a 12V 23A little finger battery. This circumstance is negative, since this battery quickly fails. However, the multimeter has a built-in warning function when the battery is running low.
This device has the following bands:
- 200mV-500V - for DC voltage;
- 200-500 V - for AC voltage;
- 200 Ohm-2000 kOhm - for resistance;
- 200uA-200mA - for DC;
- 1, 5-9 V - for battery testing.
It is not protected from damage during the application of voltage when measuring resistance. The conductive layer on low-resistance resistors burns out, which makes the values of the microammeter and ohmmeter unknown. Also, the ADC IC may fail. In this case, the device is easier to dispose of than to try to repair it. However, repairs can be carried out according to a diagram that you can draw yourself after removing the back cover of the device. In this case, you need to indicate the ratings on the sheet, after which you should attach it to the back cover of the multimeter and use it as needed.
In conclusion
In this article, we looked at how to use a multimeter. This is an inexpensive, but multifunctional device with which you can ring the connection, set the current strength, check the voltage of both DC and AC, and test batteries. Some devices allow you to measure temperature, set the operating parameters of transistors, and perform some other functions.
