For Computer Geeks

## Tuesday, 6 October 2020

Measurements & Instrumentation: Electrical measuring devices are important in following up on the operation of electrical circuits as they help the engineer and technician to know the operating conditions and conditions.

### The most important electrical measuring devices according to Ohm's law are:

#### 1- Potentiometer: Voltmetre

This device is used to measure the potential difference applied between the ends of an electrical load or to measure the voltage of a source

This device is connected in parallel or in parallel with the source or electrical load with the condition of the electric current leakage, i.e. the electrical circuit whose voltage is to be measured must be closed.

#### 2- Ammeters: Ammeters

This device is used to measure the electric current passing through an electrical load that connects this device to the load whose current is to be measured in series or series, taking into account that the electrical circuit is closed.

Measurements & Instrumentation Or in addition to the current transformers (CT), which helps to measure the current flowing in the conductors without the need to cut the conductor, but by measuring the inductive current of the conductor, which is proportional to the intensity of the current passing through it.

#### 3- Impedance measuring device: Ohmmeter

This device is used to measure the resistance of electrical loads and to ensure the validity of these loads. This device is connected to the loads whose resistance is to be measured in parallel, taking into account the absence of electric current flow, meaning that the circuit is open.

#### 4- A wattmeter

This device is used to measure the capacity of electrical loads and it contains from the inside two coils, one of which is called the current coil and is connected to the load in series, and the other is called the voltage coil and it is connected with the load in parallel.

### Types of electrical measuring devices:

In terms of showing the reading, electrical meters are divided into two types:

#### 1- Analog devices:

As it is designed with an index that moves in a gradient between the value or the measured reading

#### 2- Digital measuring devices:

They are very accurate devices that show the measured quantity or value on an electronic screen (LCD) in the form of numbers

### Electrical measurement readers are divided into two types in terms of installation:

1- A fixed type that is installed inside the electrical panels or on their doors and reads the panel data according to its function

#### These devices are of two types:

A type of reading and control in the circuit as it is set in advance, such as the relay phase relay, electronic overload, electronic thermostat, thermal controller, and others.

The mobile type used by the engineer or technician supervising the work and maintenance of electrical circuits

There are also two types:

• Analog.
• And digital.