WIDE-RANGE DIRECT CURRENT METER Russian patent published in 2025 - IPC G01R27/00 G01R19/00 

FIELD: measuring.

SUBSTANCE: invention relates to the field of control and measuring equipment and can be used in the wide-range low current meters with automatic sub-ranges switching in the reactor plants control, monitoring and protection systems, in which ionization chamber is used as detector (direct current source), when designing radiometric and dosimetric equipment, in systems for technical diagnosis of electrical equipment of railway transport, in navigation devices, in magnetic resonance imaging devices and other different fields. Novelty in the claimed invention is that the wide-range direct current meter contains overload protection module, galvanic isolation module, optical control modules, and the electrometric amplifier is made in a screen with protective earthing and includes a current compensation module, which has a second operational amplifier with a rigidly mounted resistor in the feedback circuit, wherein the input of the overload protection module is combined with the input of a wide-range direct current meter configured to receive the measured input current, and the output is connected to the inverting input connection point of the first operational amplifier with the current-setting resistor of the current compensation module, the resistor of the parallel feedback circuit of the most sensitive sub-range for measuring the input current is rigidly connected to the parallel feedback circuit of the electrometric amplifier, and the parallel feedback circuits other resistors are connected to the said circuit by means of the digitally controlled high-speed analogue keys, the galvanic isolation module input is connected to the electrometer amplifier output, and the output of the galvanic isolation module is connected to the input of the sub-band switching control unit, made on the basis of a multi-bit analogue-to-digital converter (ADC) and containing a number of outputs equal to the number of measurement sub-bands, and connected to a computing device, each optical control module is connected to the corresponding output of the sub-band switching control unit and to the corresponding input of the quick-acting analogue switch of the electrometric amplifier.

EFFECT: enlarging the range of DC force measurement, which provides measurement in the range of at least fifteen orders, as well as improving the DC force measurement accuracy.

1 cl, 1 dwg