The home master periodically needs to be measured by chain parameters. Check which voltage at the moment on the network, whether the cable does not pass, etc. For these purposes there are small devices - multimeters. With small size and cost, they allow you to measure various electrical parameters. About how to use a multimeter and talk on.
External structure and functions
Recently, specialists and radio amateurs basically use electronic models of multimeters. This does not mean that the shooter is not at all used. They are indispensable when the electronic simply does not work due to strong interference. But in most cases, we have the case with digital models.
There are different modifications of these measuring instruments with different measurement accuracy, different functionality. There are automatic multimeters in which the switch has only a few positions - they choose the measure of measurement (voltage, resistance, current) and the measurement limits The device chooses itself. There are models that can be connected to a computer. These measurements they transmit directly to the computer where they can be saved.
Automatic multimeters on the scale have only types of measurements
But most of the home masters use low-cost models of the middle class accuracy (with a bit of 3.5, which ensures accuracy of readings in 1%). These are common multimeters DT 830, 831, 832, 833. 834, etc. The last digit shows the "freshness" of modifications. Later models have a wider functionality, but for home use, these new opportunities are not critical. Working with all these models is not much different, so we will speak in general about the receptions and order of actions.
The structure of the electronic multimeter
Before using the multimeter, we will study its structure. Electronic models have a small liquid crystal screen, which displays the measurement results. Below the screen has a range switch. He rotates around his axis. The part on which the red dot or arrow is applied, it indicates the current type and range of measurements. There are labels around the switch by which the measurement type is set and their range.
General device multimeter
Below on the case there are jacks for connecting probe. Depending on the model, the nests are two or three, there are always two probe. One positive (red), the second is negative - black. The black dipstick always connects to the connector signed by "COM" or COMMON or which has the designation as "earth". Red - in one of the free nests. If the connectors are always two, there are no problems if the nests are three, it is necessary to read in the instructions, under what measurements to which the nest insert the "positive" probe. In most cases, the red dipstick is connected to the middle socket. This is how much of the measurements are carried out. The top connector is necessary if the current is gathered to 10 A (if more, then also in the middle socket).
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Where to connect the probes of the multimeter
There are models of testers in which the nests are located not to the right, but at the bottom (for example, the Multimeter of Renthante DT 181 or Hama 00081700 EM393 in the photo). There is no difference in connection in this case, there is no: black on the socket with the inscription "COM", and the red in a situation - when measuring currents up to 200 mA to 10 A - in the extreme right nest, in all other situations - on average.
Sockets for connecting probe at multimeters can be located below
There are models with four connectors. In this case, two current measurement nests are one for microtons (less than 200 mA), the second for the current of the current from 200 mA to 10 A. Usasniv, what and for what is in the device, you can begin to understand how to use a multimeter.
Switch position
The measurement mode depends on what position is the switch. At one of its ends there is a point, it is usually tinted with white or red. This end and indicates the current mode of operation. In some models, the switch is made in the form of a truncated cone or has one edge pointed. This sharp edge is also a pointer. To work it easier, you can apply bright paint to this pointing edge. It may be nail polish or some kind of paint abrasion.
Position of the measurement ranges switch at the multimeter
By turning this switch, you change the device mode. If it is vertically up, the device is turned off. In addition, there are the following provisions:
- V with a wavy feature or ACV (to the right of the "off") - measurement mode of alternating voltage;
- A with a direct feature - DC measurement;
- A with a wavy feature - the definition of alternating current (this mode is not at all multimeters, it is not available on the photo above);
- V With a direct feature or the inscription DCV (to the left of the position off) - to measure the constant voltage;
- Ω - measurement of resistance.
There is also a position for determining the gain of transistors and determining the polarity of diodes. There may be others, but their appointment must be sought in the instructions for a specific instrument.
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Measurements
The use of the electronic tester is convenient because it is not necessary to look for the desired scale, consider divisions by defining the testimony. They will be breathed on the screen with an accuracy of two decimal places. If the measured value has polarity, the "minus" sign will appear. If there is no minus, the measurement value is positive.How to measure the resistance to the multimeter
To measure the resistance, we translate the switch to the zone indicated by the letter Ω. Select any of the ranges. One dipstick apply to one entrance, the second to another. Those numbers that will be breathed on the display and have resistance to the element you measured.
How to use a multimeter for measuring resistance
Sometimes not numbers are displayed on the screen. If "jumped" 0, then it is necessary to change the measurement range to the smaller. If the words "OL" or "OVER" are highlighted, it's worth "1", the range is too small and it must be increased. That's all the tricks of measuring resistance to a multimeter.
How to measure current
To select the measurement mode, you must first determine the current constant or variable. With the measurement of AC parameters, there may be problems - this mode is far from all models. But the procedure regardless of the type of current is the same - only the position of the switch changes.D.C
So, deciding with the type of current, set the switch. Next, you need to decide which socket to connect the red probe. If you even do not know what values do not need to be expected to accidentally not burn the device, it is better to first install the dipstick in the upper (extreme left in other models) the socket that signed "10 A". If the testimony is small - less than 200 mA, rearrange the dipstick in the middle position.
Similarly, the situation is also with the choice of the measurement range: first set the most maximum range, if it turns out to be too large, switch to the next smaller. So until you see the testimony.
How to connect a multimeter for DC measurement
To measure the strength of the current, the device must be included in the chain break. Connection diagram is given in the picture. In this case, the red probe is important to install on the "+" power source and black touch the next element of the chain. Do not forget when measuring that the power is in is, work carefully. Do not touch the hands of the uninsulated ends of the probe or elements of the chain.
Alternating current
You can try the AC measurement mode on any load connected to the household power grid and thus determined the current consumed. Since in this mode, the device must be included in the chain break, difficulties may occur. You can, as in the photo below, make a special cord for measurements. At one end of the cord, the fork, on the other, is a socket, one of the wires cut, to attach two WAGO connector to the ends. They are good because they also allow the probe. After the measuring scheme is assembled, proceed to measurements.
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AC measurement by electronic multimeter
Translate the switch to the "Alternating Current" position, select the measurement limit. Note that the excess of the limits can bring the device in order. At best, the fuse will burn, at worst - the "filling" will damn. Therefore, we act on the scheme proposed above: first we put the maximum limit, then gradually reduce. (Do not forget about the permutation of probe in nests).
AC measurement circuit
Now everything is ready. First connect the load to the outlet. Can be a desk lamp. Plug insert into the network. Figures appear on the screen. This will be consumed by the lamp current. In the same way, you can measure the current consumed for any device.
Voltage measurement
The voltage is also variable or constant, respectively, select the desired position. The approach to the choice of the range here is the same: if you do not know what to expect, put the maximum, gradually switches to a smaller scale. Do not forget to check whether the probes are connected correctly, in those nests.
In this case, the measuring device is connected in parallel. For example, you can measure the battery voltage or a conventional battery. Set the switch to the position of the measurement mode of a constant voltage, as we know the expected value, select the appropriate scale. Next, we touch the battery from both sides. The numbers on the screen will be the voltage that gives this element.
How to use a multimeter to measure voltage
How to use a multimeter to measure alternating voltage? Yes, just too. Only choose the measurement limit correctly.
Conducting wires using a multimeter
This operation allows you to check the integrity of the wires. On the scale we find the sign of the transversche - a schematic image of the sound (see the photo, but there is a double mode, and there may be only a sign of the transvers). Such an image is selected because if the wire is a whole, the device makes a sound.
Call mode on the Multimeter Measurement Scale
We put the switch to the desired position, the proves are connected as usual - to the lower and middle socket. Touch one dipstick to one edge of the conductor, to another. If you hear the sound, the wire is whole. In general, as you can see, use the multimeter is easy. Everything is easy to remember.