Data Loggers Function:
The basic Data Loggers Function is to automatically make a record of the readings of instruments located at different parts of the plant. Data loggers measure and record data effortlessly as quickly, as often, and as accurately desired.
Measurement errors are eliminated and the log is permanent in a form most suited to ones requirements.
It can measure electrical output from virtually any type of transducer and log the value automatically. Since simple presentation of data for a large number of points at regular intervals of time is not sufficient, present day data loggers are designed to scan and record data very fast under fault conditions of automatic initiation. In addition, automatic data loggers are capable of giving plant performance computation and a logic analysis of alarm conditions during emergency.
A data logger processes the readings to render then immediately as recogÂnisable scientific units (°C kg/cm2, etc.). It can detect readings outside defined limits and initiates corrective action, and it can record all or selected readings on a variety of output devices, or pass them into a computer for further processing.
The measurement range, speed of measurement and operation for recorders can be different for blocks of channels or even for single channel and all this is achieved in data loggers by having preset programs. Since loggers handle the data in digital form, they can manipulate and process the reading without any loss of accuracy.
A logging sequence may be started manually by pressing a push button, or automatically by the clock. When a scan is started by the clock, the logger advances ahead by time. The clock will start logging sequences at intervals of one second, up to two hours. The log can be started and stopped on any channel.
Presently, data loggers are invariably used in power generation plants, petrochemical installations, continuous process plants, engine testing, compoÂnent evaluation, etc.
Modern data loggers are tailor made systems, designed precisely from standard modules to meet a particular requirement. They generally possess the following characteristics:
- Modularity
Systems can be expanded whenever required, simply and efficiently, often entailing little or no interruption to the working system.
- Reliability and Ruggedness
Designed to operate continuously without interruption even in the worst industrial environments.
- Accuracy
The specified accuracy is maintained throughout the period of use.
- Management Tool
In addition to simple data acquisition, there are facilities to perform many other functions, and present the results in handy form.
- Easy to Use
These communicate with operators in a logical manner, are simple in concept, and therefore easy to understand, operate and expand.