Circuits, Formulas and Tables Electrical Engineering - Basic vocational knowledge (Institut für Berufliche Entwicklung, 201 p.)
 7. Measurement Circuits
 7.1. Measurement Circuits in Direct-current Installations 7.2. Measurement Circuits in Alternating-current Installations 7.3. Measurement Circuits in Three-phase Installations

### 7.1. Measurement Circuits in Direct-current Installations

Voltage measurement (A)

Voltage measurement (B)

By connecting in series of a resistor (Rv), an extension of the measuring range of the voltmeter is obtained

Current measurement (A)

Current measurement (B)

By connecting in parallel a shunt resistor (Rp), an extension of the measuring range of the ammeter is obtained.

Voltage and current measurement for the determination of the resistance

The current-exact connection is used when the resistance (Rx) to be determined, is very high.

Current and voltage measurement for the determination of the resistance

The voltage-exact connection is used when the resistance (Rx) to be determined is very small if the resistance Rx is calculated according to the following equation: