There is a measuring device that combines the functions of several similar devices. It is called a multimeter. How to use it will be discussed in this article. It is mainly intended for measuring 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;
- current frequency measurement;
- sound probe.
Due to the fact that they were added to existing functions, a question arises for many users: how to use the multimeter?
Classification of equipment in question
All modern multimeters can be divided into:
- Digital, which are most popular, since they are relatively inexpensive, perform many functions, are easy to use.
- Arrows, in which the reading is carried out on a scale with an arrow. They have a slight error due to the difference of 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 variety with some inserts along it in the course of the presentation of the material.
Check resistance
Before this work, the multimeter should be prepared for it. The device has a toggle switch, which 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 complete de-energization of the circuits. To do this, the equipment, which will be measured resistance, is disconnected from the electrical network, or from there, batteries such as batteries are removed.
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 โ0โ either on the electronic display or using the magnetic arrow. If this does not happen, then it is necessary to carry out the adjustment using the knob "Set. 0 ". All other cases require battery replacement.
We measure a constant voltage
Consider how to use a digital multimeter to determine this indicator. Typically, the sector responsible for this measurement is divided into 5 ranges:
- 200 mV;
- 2000 mV;
- 20 V;
- 200 V;
- 2000 V.
However, their number may be different 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 (plus) is inserted into the one located slightly higher.
In order to measure the battery voltage of 1.5 V, set the switch to position 20. With the appropriate measuring probes we touch the opposite poles of the battery and look at the screen, while the number 1.49 should be displayed on it.
If the measured voltage is not known, then you need to start with 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 scoreboard. If there will be zeros in front, but some number will already appear, you can translate the device into a position that is a multiple of the number of zeros ahead in comparison with the occupied one, in which this number was fixed. This is necessary if it is necessary to obtain more accurate data. If strong accuracy is not required, then you can take readings at the stage with zeros to a significant number. Sometimes a multimeter does not burn out when a smaller range is set than the measured value, but displays โ1โ. However, you should not allow this condition too often.
We examined how to use the multimeter correctly. If you accidentally mix up the minus and plus probes, nothing bad will happen, just the number displayed on the scoreboard will be with a โ-โ sign. Small ranges are used when working with amateur circuits and transistors.
Measuring AC voltage
It doesnโt matter where the plus and minus are on the probes. 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:
Test probes are placed in a multimeter in the same way as they were inserted when measuring DC voltage. To measure the indicator in question, it is necessary to set the range 750 in the socket, since 220 V is more than 200. After the end of work, turn the device to the โOffโ position.
Check network integrity
To do this, you need to ring the last. In order to perform this operation, a device with a magnetic arrow 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 may differ due to the transient current resistance from the ends of the probes. When they open, the arrow is set to infinity on the corresponding devices, and on digital devices a reboot will start or โ1โ will appear. If the ends of the probe are leaned against the direct conductor, a zero value should appear.
If there is a built-in function for ringing circuits, it should be carried out by setting the toggle switch in this position with respect to the wires and low-resistance working circuits. In this case, a signal will be given, which makes the display unnecessary. If there is a break in the sound network, 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 device as an ammeter
In order to determine the current strength, the device is connected to an electric circuit. If bare wires are present , then the toggle switches of the device are turned off, the check is performed by a special probe. In the current circuit, the current must be equal to 0. The place where the measurements are made must be dry. Before working on your hands, it is better to wear gloves.
Capacitor check
It passes alternating current through itself. To carry out a capacitance check, the condition must be met that for the device it must be 0.25 ฮผFarad, that is, the minimum.
When performing checks carry out the following actions:
- determine the positive and negative poles of the capacitor;
- remove static electricity from it;
- the multimeter is placed in the position of dialing or determination of resistance;
- touch probes of this device to the terminals of the capacitor.
In this case, it is most convenient to use an analog (arrow) multimeter, since it controls the movement of the arrow. The capacitor is operational if the device is beeping or showing zero resistance. The displayed unit indicates that there is an open inside the capacitor.
Dial multimeter
How to use a dial multimeter? Basically, in exactly the same way, only readings are not taken electronically from a digital display, but are read on a scale, on a frozen arrow. Manufacturers released a combination - arrow-digital device. With it, you can determine the alternating and direct current, resistance and capacitance of the capacitors, test the diodes, ring the connections and check the batteries.
According to user reviews, this kind of multimeter is considered a poorer analogue in comparison with a digital device. This is due to the fact that the arrow may jam, the accuracy of the device is lower compared to digital. It is advised to use it if it is necessary to take measurements at two points simultaneously with a digital multimeter while tracking their mutual dynamics.
Use of the appliance in cars
How to use a multimeter in a car? In this case, the most popular functions are ringing and a voltmeter. The most common is the DT-832 multimeter. How to use it, we will consider further.
The number 832 indicates that the device is equipped with an audible indication. It should be operated at a temperature range of 0-40 ยฐ C. It is powered by a Krona battery. With its help it is possible to measure direct current up to 10 A, alternating voltage up to 750 V, direct up to 1000 V, resistance up to 2000 kOhm, and transistors and diodes.
A black probe is inserted into the COM socket, the two upstream are for the red variety. The current strength can be determined for additional equipment for the car. On a 220 V network, this indicator cannot be measured.
Choose a car multimeter should be based on the following provisions:
- it is better if the model is equipped with a sound alert;
- you need to choose a device that has a fuse, which can be replaced in case of an erroneous action committed by the user;
- The case must be rubberized.
In addition to the considered multimeter, other similar devices can be used in cars. The most compact, having small sizes that coincide with two matchboxes, is the DT-182 multimeter. How to use it? Similar. It is designed to measure resistance, voltage and current. It can also test transistors, diodes, and batteries to ring connections. This device is powered by a small battery type 23A, with a voltage of 12 V. This circumstance is negative, since this battery quickly fails. However, the multimeter has a built-in warning function that the battery is near the end.
This device has the following ranges:
- 200 mV-500 V - for constant voltage;
- 200-500 V - for alternating voltage;
- 200 Ohm-2000 kOhm - for resistance;
- 200 ฮผA-200 mA - for direct current;
- 1.5-9 V - for battery testing.
It is not protected against damage during voltage application when measuring resistance. The conductive layer on low-resistance resistors burns out, which makes the values โโof the microammeter and ohmmeter unknown. Also, the IC ADC may fail. In this case, the device is easier to dispose of than to try to repair. However, repairs can be carried out according to a scheme that can be drawn independently after removing the back cover of the device. At the same time, the values โโshould be indicated on the sheet, after which it should be attached to the back cover of the multimeter and used as needed.
Finally
In this article, we looked at how to use a multimeter. This is an inexpensive, but multi-functional device, with which you can ring the connection, set the current strength, check the voltage of both direct and alternating current, test the batteries. Some devices allow you to measure temperature, set the operating parameters of transistors, and also perform some other functions.