Also, this device may be called: M-250, M 250.
Voltmeter M250 - perenosnoypribor-coil system is designed to control measurements of battery voltage.
The device operates on the principle of magnetic flux in result of interaction of the permanent magnet device to the current in the winding P amki movable and the formation torque. M250 is equipped with a special magnetic shield that protects the measuring unit of magnetic field strength of 1200 A / m Create opposing points is realized by two current-carrying coil springs.
Type of scale voltmeter - uniform, indicating system - analog direct-reading. The scale has a uniform character, as the angle of deflection of the frame and the associated arrows is proportional to the strength of the current flowing through the winding frame.
Devices are resistant to shock and vibration due to the fact that the moving part is based on the spring-loaded pivot bearings. The voltmeter is enclosed in a splash-proof plastic housing.
Accuracy class - 0.5.
Power consumption M250 - 4 mA.
Measurement limits - 3B 200V, 400V.
Dimensions - 196h210h95 mm.
Scale length - 125 mm.
Changes display voltmeters M250 can be caused by:
- Changing the position of the device in any direction from the normal position at 30 ° (the value of reading changes - no more than ± 0,5%);
- The influence of an external magnetic field of 1200A / m, formed by direct current, under the most unfavorable direction of the field (the change of indications - no more than ± 0,5% of the length of full scale);
- Ambient air temperature deviation from normal (+20 ± 5 ° C) to any temperature within the operating temperature (the value of reading changes - no more than ± 0,3% of full scale value for each 10 ° C change in temperature);
- Installation of the devices on a ferromagnetic base thickness of 3 mm (change of testimony - ± 0,25% of full scale value).
Voltmeters M250 3V have a button changes the polarity, located in the lower right corner of the front of the unit. For the convenience of measuring battery voltage is applied to the device special pair of wires: one end of the probe ends, the other tip for connecting the device to the terminals.
To eliminate parallax error range is equipped with a mirror. On the front side of the enclosure is placed on 3V button to change the polarity in case of an incorrect switch, which prevents the need for switching the device.
Devices M250 withstand without damage long-term overload current or voltage equal to 120% of nominal. In addition, all devices withstand short-term (up to 5 s) overload double the rated current or rated voltage.
Operating conditions of devices M250
Temperature from -40 ° C to +60 ° C.
Relative humidity 98%.
The steady-state temperature rise of all elements of the devices over an ambient temperature caused by the heat load equal to the rated current and rated voltage of not more than:
50 ° C - for coils of wire, insulated cotton yarn, silk or nylon, impregnated with varnish, as well as for the windings of enameled wire;
65 ° C - for coils of wire with vinifleksovoy megalvinilovoy or insulation;
80 ° C - for non-insulated live parts.
The insulation resistance of electrical circuits of devices relative to the body at a temperature of +20 ± 5 ° C should not be less than:
50MOm - relative humidity 80%;
2 MW - relative humidity of 95 ± 3%.
Operating position of all types of devices horizontal.
Settling time moving part does not exceed 3 seconds.
Weight 2.7 kg.