Multimeter UM-112B 
The type UM-112B multimeter is designed for the measurements of: • D.C. and A.C. voltages • D.C. and A.C. currents • resistances The type UM-112B multimeter is found in the standard equipment not only of repair shops and testing stations but also – owing to its properly selected measuring ranges – in laboratories,especially such of research centers and schools.
It is indispensable to all professionals and amateurs that are occupied with electrical devices and equipment. General Information:
- 43 measuring ranges changed by means of a single range switch;
- Polarity change-over key switch permitting the measurements of direct current and D.C. voltage of a polarity opposite to that marked at the plug sockets without need to interchange the connecting wires;
- A specially designed moving element which is taut-band suspended minimize the instrument sensitivity to vibrations shocks, etc.
- The protection of measuring element and measuring circuit against overloads which are likely to occur as a result of faulty measuring range setting;
- A common scale for all direct and alternating current ranges what greatly facilitates readings;
- The measuring element and the measuring circuit are protected respectively by a diode system and by the fuse;
- Accurate readings, free of parallax error, owing to a narrowed and pointer and mirror scale being applied;
- Zero adjuster permitting to set the pointer to zero position without need to apply a screwdriver;
- Ease access to battery and fuse which elements can be replaced without need to dismantle the instrument;
- High accuracy of measurement;
- Pleasing appearance.
Technical specification: Direct and alternating current measurement: Nature of current | Accuracy class | No. of measuring ranges | Measuring range and values | Voltage drop approx. | Direct current | 1 | 12 | 50-100-300 µA 1-3-10 mA 30-100-300 mA 1-3-10 A | 30-60-80 mV 90 mV 90 mV 90 mV | Alternating current | 2,5 | 9 | 1-3-10 mA 30-100-300 mA 1-3-10 A | 600-500-400 mV 100-100-50 mV 50-50-150 mV | Frequency nominal range of use and reference value at alternating current measurements: 20...45...65...20000Hz. D.C. voltage measurement Accuracy class | No. of measuring ranges | Measuring range and values | Internal resistance | 1 | 10 | 30-100-300 mV 1-3-10 V 30-100-300 V | 20 kΩ/V | 1000 V | 1 MΩ | Accuracy class | No. of measuring ranges | Measuring range and values | Internal resistance | Frequency nominal range of use and reference value | 2,5 | 7 | 1V | 100 Ω | 20..45..65..10000 Hz | 3V | 1000 Ω | 20..45..65..20000 Hz | 10V 30V 100-300 V
| 1 kΩ/V | 1 000 V | 20..45..65..2000 Hz | Indication range | Measuring range and values | Scale mid-point | Supply voltage | 0...2 kΩ 0...20 kΩ 0...200 kΩ 0...2 MΩ 0...20 MΩ | 0,01 kΩ...0,4 kΩ 0,1 kΩ...4 kΩ 1 kΩ...40 kΩ 10 kΩ...400 kΩ 0,1 MΩ...4 MΩ | 75 Ω 750 Ω 7,5 kΩ 75 kΩ 750 kΩ | 1,5 V 1,5 V 1,5 V 10,5 V 100,5 V | - Ohmmeter supply battery cells:
| type R-14 (1,5 V) and 6F-22 (9 V); | The 0...20 MΩ range is, in addition, energized from an external D.C. supply 90 V;
| - Accuracy class for resistance measuring:
| | - measuring range: | 10%; | - indication range: | 1,5% scale length; | - Scale length (voltage and current measuring):
| 100 mm; | - Scale length (resistance measuring):
| 75 mm; | | 3 kV; | - Overall dimensions (width x length x height):
| 186 x 134 x 67 mm; | | 0,9 kg; | | | Nominal operating conditions: - Ambient temperature range:
| 13...23...33°C; | - Ambient air relative humidity:
| 25...40...75...85%; | - Operating position of tester:
| horizontal. |
Standard equipment: - Test leads, crocodile clips;
Others information:Catalogue card Operation manual |