Recording instruments are those instruments that record the continuous variation in magnitude of an electrical quantity with respect to time.
The term recording instrument refers to an instrument that captures data or variations in electrical quantities over time. There are both analog and digital recording instruments available.
The instrument is used in environments where continuous readings of circuit conditions are necessary. A record is kept for the purpose of referencing or performing computations in the future.
Physical quantities are recorded using recording instruments in the form of graphs. A variation of the quantities over time is also recorded.
Recording Instruments – Examples
Video cameras, thermoscopes, electrocardiograph (ECG) machines, energy meters, fitness trackers, pedometers, graphical temperature meters, wheater monitoring devices, etc. are examples of recording instruments.
An analog graphical temperature meter, for example, is equipped with graph paper and a pen. As the temperature changes over time, accordingly, the pen will draw a continuous graph. After reading this graph, we can determine what time the temperature was at that time.
Data can be stored in digital recording instruments by using memory. In contrast to analog recording instruments, digital recording instruments are capable of storing data for a longer period of time.
How to convert indicating instruments into recording instruments?
A continuous reading is recorded by the indicating instrument, but the variations in readings must be observed continuously by an observer to store the data. In order to obtain the recording instrument, one must improve the design of an indicating instrument. By replacing the pointer on the indicating instrument with an ink pen, the indicating instrument is transformed into a recording instrument.
The ink pen is deflected in order to record the measurements on graph paper. At a constant speed, the pen rotates continuously on the drum. A continuous reading of the variant physical quantity is obtained by tracing the path of the pen.
A traced chart is used to determine the magnitude of the quantity. In power stations, where continuous reading is required, the instruments are used.
Difference between Indicating and Recording Instruments
Despite measuring data every fraction of a second, indicating instruments did not store any data. Thus, we can always view the current data, but we cannot access the previous or past data.
The recording instruments, however, measure data each fraction of a second, but the difference is that they record each data as it relates to time.
As a result, here we are able to obtain both current and previous data. There are various types of indicating instruments, such as ammeter, voltmeter, and wattmeter.
The recording instrument is actually a combination of an indicating instrument and a mechanism for storing or writing data. Indicating instruments measure the data every fraction of time, whereas storing functionality record the data with time. There are many applications and uses for each of the instruments.