You will need
  • resistor, an ohmmeter, a multimeter, a magnifying glass.
The easiest way to determine the resistance of the resistor is to learn about it from the relevant documentation. If the resistor is purchased as a standalone item, find the supporting documents (invoice, warranty card, etc.). Find in them the value of the resistor. Most likely, the resistance value will be specified next to the part name, for example, a resistor of 4.7 K. In this case, the number means the value of the resistor, and the letter (s) is a unit of measurement. Options K, K, Kom, kom, Kom, kom correspond to kiloohm.The same designation with the letter "M" instead of "to" - megohms. If the letter "m" will be lowercase (small), theoretically this corresponds to a milliohm. However, in practice, such resistors are not normally sold, but are made independently from several coils of special wire. Therefore, combinations with the letter "m" can be attributed to the megohms (in unusual cases, it is better to specify).The lack of after the number of units or the presence of the word "Om" or "om" means, respectively, in Ohms. (in practice, may mean that the seller simply does not have the unit).
If the resistor is part of an electric (electronic) devices take the electrical diagram of this device. If no schematic, try to find it on the Internet. Look at the diagram of the corresponding resistor. Resistors are indicated by small rectangles with lines emerging from the short sides. Inside the rectangle can be dashes (represent power). To the designation of the resistor (rectangle) is usually the letter R and a numeral indicating the ordinal number of the resistor in the circuit, for example, R10. After the designation of the resistor indicate its value (slightly to the right or below). If the resistance of the resistor is not specified, the view in the lower part of the diagram – sometimes resistor values (grouped by values) are in there.
If you have a ohmmeter or multimeter, just connect the device to the conclusions of the resistor and record the readings. Pre-multimeter switch to the measurement mode of resistance. If the ohmmeter "rolls" or on the contrary, shows a very small value, set it to any range. If the resistor is part of the scheme, the pre-wipaire it, otherwise the readings will probably be incorrect (smaller).
The value of the resistor can also be identified by its marking. If the denomination consists of two digits and one letter (typically for the old "Soviet" parts), then use the following rule:
The letter is put in place and the decimal point represents a multiple of the prefix:K – kilo Ohm;
M – Megohm;
E – units, i.e. in this case Om.If the value of the resistor is an integer, then the corresponding letter is used at the end of the designation (69К = 69 kOhm). If the resistance of the resistor is less than one letter is placed before the number (M15 = 0.15 Mω = 150 kω). In fractional denominations of the letter is between numbers (9Е5 = 9.5 Ohm).
Numbers consisting of three digits, remember the following simple rule: the first two digits need to add as many zeros as indicated by the third digit. For example, 162, 690, 166 interpreted as follows:162 = 16’00 Ohms = 1.6 kω;
690 = 69’ Om = 69 Ohms;
166 = 16’000000 Ohm = 16 MOhm.
If the value of the resistor is marked with colored stripes, turn it off (or turn) to the individual (apart from three) strip was to the right. Then, using the following table, match colors, put the color stripes in the numbers are: black - 0;
brown - 1;
red - 2;
- orange - 3;
- yellow - 4;
green - 5;
blue - 6;
purple - 7;
gray - 8;
- white - 9.After receiving a three-digit number, use the rule described in the preceding paragraph. So for example, if the color of the three stripes in the following order, i.e. from left to right (red - 2, orange - 3, yellow - 4), we obtain the number 234, which corresponds to the nominal value of 230000 Ohms = 230 kω. By the way, the above table is very easy to remember. Order medium colors corresponding to the rainbow, and extreme color to the end of the list become lighter.