Как мультиметром мерить омы: Как измерить сопротивление мультиметром – что надо знать

Фотомануал как измеряется сопротивление мультиметром

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Одной из основных функций мультиметра является проверка сопротивления. Эта задача может появиться при ремонте автомобиля или бытовой электронике. Зная номинальные показатели резистора, лампы накаливания или иного проводника можно установить его исправность и пригодность для дальнейшей эксплуатации.

Пошаговое руководство

На всех мультиметрах имеется обязательное гнездо СОМ — в него необходимо вставить штеккер с черным щупом. На рисунках показано, где располагается это гнездо в популярных моделях:

Гнездо СОМ мультиметра Clarke

Гнездо СОМ на мультиметре Mastertech

Стрелкой показано гнездо СОМ мультиметра Facom 714

Гнездо СОМ мультиметра VA17

После этого нужно найти гнездо для измерения сопротивления. обозначается оно символом VΩmA или совпадать с гнездом для измерения частоты, тогда оно обозначается VΩHz и воткнуть в него красный щуп. Для примера несколько мультиметров с разными обозначениями:

Fluke 87V разъем совмещен с вольтметром, диодным датчикком

Kemot — гнездо сопротивления совмещено с вольтметром, гнездом для измерения емкости аккумулятора

Mastech — сопротивление, вольтметр, тестер для диодов в одном гнезде

Fluke 287 Температура, сопротивление, диод, вольтметр в одном гнезде

 

 С помощью поворотной ручки перевести мультиметр в режим измерения сопротивления. Он обозначен Ω (омега) и проверить работу прибора. Для этого нужно замкнуть щупы. Сопротивление должно составить 0,3 — 0,8 Ом. Если показывает бо́льшую цифру — значит провода или щупы пришли в негодность и их нужно заменить.

Щупами или «крокодильчиками» касаемся измеряемого элемента и смотрим на экран:

На экране отображается сопротивление замкнутой цепи

Важно знать. Если при измерении сопротивления мультиметр показывает единицу в крайнем левом положении — значит цепь разомкнута. Такое же сопротивление должны показывать «пустые» щупы.

Разомкнутая цепь — единица в левом положении

Большинство мультиметров с функцией измерения сопротивления имеют несколько диапазонов чувствительности. Если вы не знаете номинального сопротивления измеряемой цепи — чувствительность можно подобрать вращением рукоятки на передней панели:

Рукояткой выставляем необходимую чувствительность

Как видно на примере выше (мультиметр DT9202A) , чувствительность можно установить в нескольких диапазонах от 200 Ом до 2 мегаОм. Просто вращайте рубильник вправо до тех пор, пока показания на табло не станут изменяться — это и будет правильно выбранный диапазон.

Важно знать. При выставлении высокой чувствительности щупы могут реагировать на прикосновение к ним пальцев. Поэтому не касайтесь металлических контактов, иначе мультиметр будет измерять сопротивление вашего тела, а не цепи.

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Пояс электромонтажника — что это такое Набор диэлектрических отвёрток в быту Как проверяют светодиод с помощью мультиметра — пошаговое руководство Стоит ли покупать набор электрика НЭУ-М или лучше сначала посчитать? 90000 How to Use a Multimeter to Measure Voltage, Current and Resistance 90001 90002 What is a Multimeter? 90003 90004 A digital multimeter or DMM is a useful test instrument for measuring voltage, current and resistance, and some meters have a facility for testing transistors and capacitors. You can also use it for checking continuity of wires and fuses. If you like to DIY, do car maintenance or troubleshoot electronic or electrical equipment, a multimeter is a handy accessory to have in your home toolkit.90005 90004 90007 If you have any questions, just leave a comment at the end of this «how to» guide. Also if you find this article useful, please share a link to it on Facebook, Pinterest or other social media using the easy share buttons. 90008 90005 90004 90007 Thanks! 90008 90005 90002 Volts, Amps, Ohms — What Does it All Mean? 90003 90004 Before we learn how to use a multimeter, we need to become familiar with the quantities we are going to be measuring. The most basic circuit we will encounter is a voltage source, which could be connected to a load.The voltage source could be a battery or a mains power supply. The load might be an appliance such as a bulb or electronic component called a 90007 resistor. 90008 The circuit can be represented by a diagram called a 90007 schematic. 90008 In the circuit below, the voltage source V creates an electrical pressure which forces a current I to flow around the circuit and through the load R. Ohm’s Law tells us that if we divide the voltage V by the resistance R, measured in ohms, it gives us a value for the current I in amps: 90005 90022 90004 V / R = I 90005 90025 90002 Quantities and Terms Used in Electrical Engineering 90003 90028 90029 Volts 90030 90031 90004 This is the pressure between two points in an electrical circuit.It could be measured across the voltage source or other components connected in the circuit. 90005 90028 90029 Amps 90030 90031 90004 This is a measure of the current flowing between two points in an electrical circuit. 90005 90028 90029 Ohms 90030 90031 90004 A measure of the resistance to flow in a circuit. 90005 90028 90029 Voltage Source 90030 90031 90004 This produces a current flow in a circuit. It could be a battery, portable generator, mains supply to a home, alternator on your car engine or bench power supply in a lab or workshop.90005 90028 90029 Load 90030 90031 90004 90029 90030 A device or component which draws power from a voltage source. This could be an electronic resistor, bulb, electric heater, motor or any electrical appliance. A load has a resistance measured in ohms. 90005 90028 90029 Ground 90030 90031 90004 This is usually the point in a circuit to which the negative terminal of a battery or power supply is connected. 90005 90028 90029 DC 90030 90031 90004 Direct current. Current flows only one way from a DC source, an example of which is a battery.90005 90028 90029 AC 90030 90031 90004 Alternating Current. Current flows one way from a source, reverses, and then flows the other way. This happens many times a second at a rate determined by the 90007 frequency 90008 which is typically 50 or 60 hertz. The mains supply in a home is AC. 90005 90028 Polarity 90031 90004 A term used to describe the direction of flow of current in a circuit or which points are positive and which are negative wrt a reference point. 90005 90004 90029 For more detailed information about these quantities and terms, take a detour to my other article: 90030 90005 90004 Volts, Watts, Amps, Kilowatt Hours, What Does it All Mean? — The Basics of Electricity 90005 90002 What Does a Multimeter Measure? 90003 90004 A basic multimeter facilitates the measurement of the following quantities: 90005 90094 90095 DC voltage 90096 90095 DC current 90096 90095 AC voltage 90096 90095 AC current (not all basic meters have this function) 90096 90095 Resistance 90096 90095 Continuity — indicated by a buzzer or tone 90096 90107 90004 In addition meters may have the following functions: 90005 90094 90095 Capacitance measurement 90096 90095 Transistor HFE or DC current gain 90096 90095 Temperature measurement with an additional probe 90096 90095 Diode test 90096 90095 Frequency measurement 90096 90107 90004 The value measured by the instrument is indicated on an LCD display or scale.90005 .90000 How to Measure Resistance with a Multimeter »Electronics Notes 90001 90002 Knowing how to measure resistance with multimeter is easy — here we proovide some guidleines about how to make resistance measurements with a multimeter & provide some hints & tips. 90003 90004 90005 90006 Multimeter Tutorial Includes: 90007 90008 Test meter basics Analogue multimeter How does an analogue multimeter work DMM digital multimeter How a DMM works DMM accuracy & resolution How to buy best digital multimeter How to use a multimeter Voltage measurement Current measurements Resistance measurements Diode & transistor test Fault finding transistor circuits 90009 90004 90005 One important measurement that can be made with a multimeter is a resistance measurement.Not only can these be made to check the accuracy of a resistor, or check it is functioning correctly, but resistance measurements can be required in many other scenarios as well. 90009 90005 It may be to measure the resistance of an unknown conductor, or it may be to check for short circuits and open circuits. 90009 90005 In fact there are many instances where measuring resistance is of great interest and importance. In all these cases a multimeter is an ideal piece of test equipment for measuring resistance 90009 90017 Resistance measurement basics 90018 90019 When measuring resistance, all musltimeters use exactly the same principle whether they are analogue multimeters or digital multimeters.In fact other forms of test equipment that measure resistance also use the same basic principle. 90009 90019 The basic idea is that the multimeter places a voltage at the two probes and this will cause a current to flow in the item for which the resistance is being measured. By measuring the resistance it is possible to determine the resistance between the two probes of the multimeter, or other item of test equipment. 90009 90017 How to measure resistance with an analogue multimeter 90018 90019 Analogue multimeters are good at measuring resistance, although they are a few points to note about the way in which it is done.90009 90005 The first point to note is that as the meter itself responds to current flowing through the component under test. A high resistance corresponds to a low current and the meter needle settles on on the left hand side of the dial, and a low resisatnce corresponds to a higher current and the meter needle deflects more so it appears on the right hand side of the dial as shown below. 90009 90005 It will also be noticed that the calibrations become much closer together as the resistance becomes higher, i.e. on the left hand side of the dial. 90009 90031 Analogue multimeter face calibrations 90019 Another aspect of using an analogue multimeter for measuring resistance is that the meter needs to be «zero’ed» before making a measurement. This is done by connecting the two probes together so that there is a short circuit, and then using the «zero» control to give full scale deflection on the meter, i.e. zero ohms. 90009 90005 Each time the range is changed, the meter needs to be zero’ed as the position may change from one range to the next.The meter needs to be zero’ed because the full scale deflection will change according to aspects such as the state of the battery. 90009 90019 There are a few simple steps required to make a resistance measurement with an analogue multimeter: 90009 90038 90039 Select the item to be measured: This may be anything where the resistance needs to be measured and estimate what the resistance may be. 90040 90039 Insert the probes into the required sockets Often a multimeter will have several sockets for the test probes.Insert these or check they are already in the correct sockets. Typically these might be labelled COM for common and the other where the ohms sign is visible. This is normally combined with the voltage measurement socket. 90040 90039 Select the required range The analogue multimeter needs on and the required range selected. The range selected should be such that the best reading can be obtained. Normally the multimeter function switch will be labelled with the maximum resistance reading. Choose the one where the estimated value of resistance will be under but close to the maximum of the range.In this way the most accurate resistance measurement can be made. 90040 90039 Zero the meter: The meter needs to be zero’ed. This is done by firmly placing the two probes together to give a short circuit and then adjusting the zero control to give a zero ohms (full scale deflection) reading. This process needs to be repeated if the range is changed. 90040 90039 Make the measurement With the multimeter ready to make the measurement the probes can be applied to the item that needs to be measured.The range can be adjusted if necessary. 90040 90039 Turn off the multimeter Once the resistance measurement has been made, it is wise to turn the function switch to a high voltage range. In this way if the multimeter is used to again for another type of reading then no damage will be caused if it is inadvertently used without selecting the correct range and function. 90040 90051 90052 90019 Analogue multimeters are ideal pieces of test equipment for measuring resistance. They are relatively cheap and they offer a reasonably good level of accuracy and general performance.They normally provide a level of accuracy that is more than sufficient for most jobs. 90009 90017 How to measure resistance with an digital multimeter, DMM 90018 90019 Measuring resistance with a digital multimeter is easier and faster than making a resistance measurement with an analogue multimeter as there is no need to zero the meter. As the digital multimeter gives a direct reading of the resistance measurement, there is also no equivalent of the reverse reading found on the analogue multimeters.90009 90019 There are a few simple steps required to make a resistance measurement with a digital multimeter: 90009 90038 90039 Select the item to be measured: This may be anything where the resistance needs to be measured and estimate what the resistance may be. 90040 90039 Insert the probes into the required sockets Often a digital multimeter will have several sockets for the test probes. Insert these or check they are already in the correct sockets. Typically these might be labelled COM for common and the other where the ohms sign is visible.This is normally combined with the voltage measurement socket. 90040 90039 Turn on the multimeter 90040 90039 Select the required range The digital multimeter needs on and the required range selected. The range selected should be such that the best reading can be obtained. Normally the multimeter function switch will be labelled with the maximum resistance reading. Choose the one where the estimated value of resistance will be under but close to the maximum of the range. In this way the most accurate resistance measurement can be made.90040 90039 Make the measurement With the multimeter ready to make the measurement the probes can be applied to the item that needs to be measured. The range can be adjusted if necessary. 90040 90039 Turn off the multimeter Once the resistance measurement has been made, the multimeter can be turned off to preserve the batteries. It is also wise to turn the function switch to a high voltage range. In this way if the multimeter is used to again for another type of reading then no damage will be caused if it is inadvertently used without selecting the correct range and function.90040 90051 90019 Digital multimeters are ideal pieces of test equipment for measuring resistance. They are relatively cheap and they offer a high level of accuracy and general performance. 90009 90017 General precautions when measuring resistance 90018 90019 As with any measurement, when measuring resistance, there are some precautions to observe. In this way damage to the multimeter can be prevented, and more accurate measurements can be made. 90009 90081 90039 90006 90084 Measure resistance when components are not connected in a circuit: 90085 90007 It is always advisable 90006 not 90007 to measure the resistance of an item that is in a circuit.It is always best to make the measurement of the component on its own out of the circuit. If a measurement is made in-circuit, then all the other components around it will have an effect. Any other paths that will allow current to pass will affect the readings, making them inaccurate to some degree. 90040 90039 90006 90084 Remember to ensure the circuit under test is not powered on 90085 90007 Under some circumstances it is necessary to measure resistance values ​​actually on a circuit. When doing this it is 90006 very important to ensure the circuit is not powered on 90007.Not only will any current flowing in the circuit invalidate any readings, but should the voltage be high enough, the current resulting could damage the multimeter. 90040 90039 90006 90084 Ensure capacitors in a circuit under test are discharged. 90085 90007 Again when measuring resistance values ​​in a circuit, it is necessary to ensure that any capacitors in the circuit are discharged. Any current that flows as a result of them will cause the meter reading to be altered. Also any capacitors in the circuit that are discharged may charge up as a result of the current from the multimeter and as a result it may take a short while for the reading to settle.90040 90039 90006 90084 Remember diodes in a circuit will cause different readings in either direction 90085 90007 When measuring resistance in a circuit that includes diodes the value measured will be different if the connections are reversed. This is because the diodes only conduct in one direction. 90040 90039 90006 90084 Leakage path through fingers can alter readings in some cases. 90085 90007 When making some resistance measurements it is necessary to hold a resistor or component onto the multimeter test probes.If high resistance measurements are being made the leakage path through the fingers can become noticeable. Under some circumstances the resistance path through fingers can be measured at just a few megohms, and as a result this can become significant. Fortunately the levels of voltage used in most multimeters when measuring resistance is low, but some specialised meters may use much higher voltages. It is wise to check. 90040 90116 90019 Measuring resistance with a multimeter is very easy and convenient.When looking at how to measure resistance, it is quite straightforward for both analogue and digital multimeters and the process is virtually the same in both instances, although readings may not be quite as easy to take if the resistance is high and the measurement needs to be taken where the calibrations are close together. Nevertheless whatever test equipment is used, resistance is easy to measure. 90009 90005 90006 More Test Topics: 90007 90008 Data network analyzer Digital Multimeter Frequency counter Oscilloscope Signal generators Spectrum analyzer LCR meter Dip meter, GDO Logic analyzer RF power meter RF signal generator Logic probe Time domain reflectometer Vector network analyzer PXI GPIB Boundary scan / JTAG 90008 90006 90084 Return to Test menu.. . 90085 90007 90009 .90000 How to Measure Current with a Multimeter »Electronics Notes 90001 90002 A multimeter provides one of the easiest ways to measure alternating and direct current (AC & DC). We provide some of the key guidelines. . . 90003 90004 90005 90006 Multimeter Tutorial Includes: 90007 90008 Test meter basics Analogue multimeter How does an analogue multimeter work DMM digital multimeter How a DMM works DMM accuracy & resolution How to buy best digital multimeter How to use a multimeter Voltage measurement Current measurements Resistance measurements Diode & transistor test Fault finding transistor circuits 90009 90004 90011 It is often necessary to know how to measure current using a multimeter.Current measurements are easy to make, but they are done in a slightly different way to the way in which voltage and other measurements are made. However current measurements often need to be made to find out whether a circuit is operating correctly, or to discover other facts associated with its current consumption. 90009 90005 Current is one of the basic electrical / electronic parameters, and therefore it is often necessary to measure the current flowing in the ciricuit to check its operation.90009 90005 90002 90017 … both digital and analogue multimeters are able to measure current very easily …. 90018 90003 90009 90021 90011 Current measurements can be made with a variety of test instruments, but the most widely used pieces of test equipment for making current measurements is a digital multimeter. These items of test equipment are widely available and at very reasonable prices. 90009 90024 Current measurement: basics 90025 90011 Current measurements are made in a different way to voltage and other measurements.Current consists of a flow of electrons around a circuit, and it is necessary to be able to monitor the overall flow of electrons. In very simple circuit is shown below. In this there is a battery, a bulb which can be used as an indicator and a resistor. To change the level of current flowing in the circuit it is possible to change the resistance, and the amount of current flowing can be gauged by the brightness of the bulb. 90009 90028 A simple circuit in which to measure current 90011 When using a multimeter to measure current, the only way that can be used to detect the level of current flowing is to break into the circuit so that the current passes through the meter.Although this can be difficult at times, it is the best option. A typical current measurement can be made as shown below. From this it can be seen that the circuit in which the current is flowing has to be broken and the multimeter inserted into the circuit. In some circuits where current may often need to be measured, terminals with a shorting link may be added to facilitate the current measurement. 90009 90031 How to measure current using a multimeter 90011 In order that the multimeter does not alter the operation of the circuit when it is used to measure current, the resistance of the meter must be as low as possible.For measurements of around an amp, the resistance of a meter should be much less than an ohm. For example if a meter had a resistance of one ohm, and a current of one amp was flowing, then it would develop a voltage of one volt across it. For most measurements this would be unacceptably high. Therefore resistances of meters used to measure current are normally very low. 90009 90024 How to measure current with an analogue multimeter 90025 90011 It is quite easy to use an analogue meter to measure electrical current.There are a few minor differences in way that current measurements are made, but the same basic principles are used. 90009 90038 90005 90002 90017 … analogue multimeters are also able to measure current easily and accurately …. 90018 90003 90009 90011 When using the analogue multimeter it is possible to follow a number of simple steps: 90009 90047 90048 Insert the probes into the correct connections — this is required because there may be a number of different connections that can be used.Be sure to get the right connections as there may be separate connections for very low or very high current ranges. 90049 90048 Set switch to the correct measurement type (i.e. to measure current) and range for the measurement to be made. When selecting the range, ensure that the maximum for the particular range chosen is above that anticipated. The range on the multimeter can be reduced later if necessary. However by selecting a range that is too high, it prevents the meter being overloaded and any possible damage to the movement of the meter itself.90049 90048 When taking the reading, optimise the range for the best reading. If possible adjust it so that the maximum deflection of the meter can be gained. In this way the most accurate reading will be gained. 90049 90048 Once the reading is complete, it is a wise precaution to place the probes into the voltage measurement sockets and turn the range to maximum voltage position. In this way if the meter is accidentally connected without thought for the range to be used, there is little chance of damage to the meter.This may not be true if it left set for a current reading, and the meter is accidentally connected across a high voltage point! 90049 90056 90024 How to measure current with a digital multimeter 90025 90011 To measure current with a digital multimeter it is possible to follow a few simple steps: 90009 90047 90048 Turn the meter on 90049 90048 Insert the probes into the correct connections — in many meters there are a number of different connections for the probes. Often one labelled common into which the black probe is normally placed.The other probe should be entered into the correct socket for the current measurement to be made. Sometimes there is a special connection for current measurements, and sometimes a separate one for either low or high current measurements. Select the correct one for the current measurement to be made. 90049 90048 Set main selector switch on the meter switch to the correct measurement type, (i.e. current) and range for the measurement to be made. When selecting the range, ensure that the maximum range is above the expected reading anticipated.The range on the DMM can then be reduced as necessary. However by selecting a range that is too high, it prevents the meter being overloaded. 90049 90048 When the measuring the current, optimise the range for the best reading. If possible enable all the leading digits to not read zero, and in this way the greatest number of significant digits can be read. 90049 90048 Once the reading is complete, it is a wise precaution to place the probes into the voltage measurement sockets and turn the range to maximum voltage.In this way if the meter is accidentally connected without thought for the range used, there is little chance of damage to the meter. This may not be true if it left set for a current reading, and the meter is accidentally connected across a high voltage point! 90049 90056 90011 Following these steps it is very easy to measure current using any digital multimeter. 90009 90024 Alternative methods of measuring current 90025 90005 The most obvious method to measure current with a multimeter is to break the circuit and apace a meter actually within the circuit.However it is not the only method that can be used. 90009 90005 There are some methods that can be implemented that do not require the circuit to be broken and a meter placed in series. 90009 90005 These methods are often used where it is important not to break the circuit, and methods which sense the current in one way or another are used. 90009 90005 The accuracy may often be almost as good as placing a meter in circuit, but they may require components to already be in place, or different types of sensor to be used.90009 90024 Using a series resistor to measure current 90025 90005 This method for measuring current can bring some advantages to some circumstances when it is foreseen that current may need to be measured on a regular basis within a circuit. 90009 90005 This current measurement technique entails placing a small resistor of a convenient value into the circuit. Normally one end of the resistor is at ground potential to avoid the risk of either high voltages of accidental shorts to ground while making the test.90009 90091 Current measurement technique inserting series resistor into the circuit. 90005 By measuring the voltage across the resistor the current can easily be calculated. 90009 90005 For example of a 10Ω resistor is placed in circuit and a reading of 100 mV is detected across it, then using Ohms Law it can be deduced that the current is V / R = 0.1 / 10 = 10 mA. 90009 90005 When using this method of measuring current, the value of the resistor must be sufficiently accurate for the measurements to be made.Any tolerance into e resistor will give a similar tolerance not he measurement. Fortunately many measurements in this situation do not need extreme accuracy, and therefore even 10% resistors will be sufficiently accurate — 2% may also be adequate depending upon the tolerances needed. 90009 90005 In the case shown, the series resistor used for the current measurement is placed close to ground, and also it is bypassed with a capacitor to bypass any signal to ground. This is particularly important if the circuit is used at radio frequencies, RF as it will help prevent any signal being radiated along the test meter leads.90009 90024 Current measurement technique using a current sensor / coil 90025 90005 If it is not possible to break into the circuit in any way, it is possible to use a current sensor. 90009 90005 Current sensors normally come in the form of a sensor that is placed around the current carrying conductor. It is able to detect the current flowing in the conductor and in this way give a reading. 90009 90005 These sensors often come as part of a complete meter, so it is often not possible to use a standard multimeter for this type of test.90009 90005 There are several different types of sensor / meter that can be used this current measurement technique. 90009 90110 90048 90006 90017 Current transformer: 90018 90007 One of the most common forms of current sensor is referred to as a current clamp. It consists of a split ferrite or soft iron ring onto which a coil is wound — one on each half. The core is passed over the conductor in which the current needs to be measured and the two halves of the core clamped in place.In this way, the assembly acts like a transformer, the clamp coils picking up the magnetic field from the current flowing in the conductor. As the overall assembly is effectively a transformer, this current measurement technique only works for AC. Also meters using this normally come as a separate «Clamp Meter». 90049 90048 90006 90017 Hall effect sensor: 90018 90007 The Hall Effect sensor using a different technology. It is able to measure both AC and DC flowing in a conductor. It is often used in conjunction with oscilloscopes, and high-end digital multimeters, although their use is becoming more widespread.90049 90123 90005 There are other similar current measurement techniques using sensors, but the current clamp and the Hall effect sensors are the most common. 90009 90024 How to measure ac current with a multimeter 90025 90005 It is often necessary to measure AC current. Although the same basic steps are used for taking the AC current measurement as when a normal DC measurement is taken, there are a few additional points to note. 90009 90110 90048 90006 90017 AC setting required: 90018 90007 The differences in the measurement result from the fact that the multimeter has to rectify the alternating waveform to enable it to measure AC current.For a digital multimeter the main difference is that the measurement type switch must be set to measure AC current rather than DC current. 90049 90048 90006 90017 Analogue meters require rectifier: 90018 90007 For an analogue multimeter the situation is a little different. As an analogue multimeter does not contain any active electronics, the diode rectifier used to rectify the alternating waveform has a certain turn on voltage and this will affect the low voltage end of some scales. Some meters may not be able to measure AC current, or they will have very restricted ranges.90049 90123 90011 Although it is not as common to measure electrical current as it is to measure voltage, it is nevertheless and important ability to be able to measure current. Also knowing how to measure current to gain the best of the multimeter is also important. 90009 90005 90006 More Test Topics: 90007 90008 Data network analyzer Digital Multimeter Frequency counter Oscilloscope Signal generators Spectrum analyzer LCR meter Dip meter, GDO Logic analyzer RF power meter RF signal generator Logic probe Time domain reflectometer Vector network analyzer PXI GPIB Boundary scan / JTAG 90008 90006 90017 Return to Test menu.. . 90018 90007 90009 .90000 How to Use a Multimeter 90001 Favorited Favorite 48 90002 Measuring Resistance 90003 90004 Normal resistors have color codes on them. If you do not know what they mean, that’s ok! There are plenty of online calculators that are easy to use. However, if you ever find yourself without internet access, a multimeter is very handy at measuring resistance. 90005 90004 Pick out a random resistor and set the multimeter to the 20kΩ setting.Then hold the probes against the resistor legs with the same amount of pressure you when pressing a key on a keyboard. 90005 90004 The meter will read one of three things, 90009 0.00 90010, 90009 1 90010, or the 90009 actual resistor value 90010. 90005 90016 90017 90004 In this case, the meter reads 0.97, meaning this resistor has a value of 970Ω, or about 1kΩ (remember you are in the 20kΩ or 20,000 Ohm mode so you need to move the decimal three places to the right or 970 Ohms) .90005 90020 90017 90004 If the multimeter 90009 reads 1 90010 or displays 90009 OL 90010, it’s overloaded. You will need to try a higher mode such as 90009 200kΩ 90010 mode or 90009 2MΩ 90010 (megaohm) mode. There is no harm if this happen, it simply means the range knob needs to be adjusted. 90005 90020 90017 90004 If the multimeter reads 90009 0.00 90010 or nearly zero, then you need to lower the mode to 90009 2kΩ 90010 or 90009 200Ω 90010. 90005 90020 90043 90004 Remember that many resistors have a 5% tolerance.This means that the color codes may indicate 10,000 Ohms (10kΩ), but because of discrepancies in the manufacturing process a 10kΩ resistor could be as low as 9.5kΩ or as high as 10.5kΩ. Do not worry, it’ll work just fine as a pull-up or general resistor. 90005 90004 Let’s drop the meter down to the next lowest setting, 2K & ohm ;. What happens? 90005 90004 Not a whole lot changed. Because this resistor (a 1K & ohm;) is less than 2K & ohm ;, it still shows up on the display. However, you’ll notice that there is one more digit after the decimal point giving us a slightly higher resolution in our reading.What about the next lowest setting? 90005 90004 Now, since 1k & ohm; is greater than 200 & ohm ;, we’ve maxed out the meter, and it is telling you that it is overloaded and that you need to try a higher value setting. 90005 90004 As a rule of thumb, it’s rare to see a resistor less than 1 Ohm. Remember that measuring resistance is not perfect. Temperature can affect the reading a lot. Also, measuring resistance of a device while it is physically installed in a circuit can be very tricky.The surrounding components on a circuit board can greatly affect the reading. 90005 90054 90054 ← Previous Page 90056 90057 Measuring Voltage 90058 .