DATA LOGGING SYSTEM

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Introduction
In the field of engineering, probably the most important aspect is collection, analysis and storage of on-field data. This broadly can be classified as “Data Logging”. Data logging has seen a repertoire of changes with progressing technology. Initially, what started as measurements with standard devices like thermometers, hygrometers, barometers has now become ever more accurate, fast and reliable with dedicated sensors to measure virtually any given physical quantity.


Data Loggers as of today are of two types:
1.Data Logger with on board memory: Here, data collection is done, and gathered data is stored on an onboard memory. Later, the device is connected to a PC and data is transferred for analysis.
2.Data Logging with transmission facility: This will collect a single parameter say temperature and keep a record of it in its buffer. Once the buffer is near its full capacity, the Data Logger transmits data to a remote host where it is analyzed.
More recently, Data Loggers having RF communication have gained importance, as they are able to communicate over large distances.
With these facts in mind, we have tried to obtain an integrated approach of the above points, as well as to make the device portable and capable of handling more than one data types. The objective of this project is not only data acquisition, but also its analysis and display of Real Time Plots of the measured values.



1)Working for Temperature Sensor-
We have used the digital temperature IC ADT75. It is a generic IC commonly called as the temperature IC75. It is manufactured by various semi-conductor companies like Analog Devices, Texas Instruments, National Semiconductors and others.
Analog Devices manufactures it under the name of ADT 75, National Semiconductors manufactures it under the name of LM75 whereas T.I. manufactures it by the name TMP75. It must be understood that all these ICs are pin to pin matches for the other ones. We decided to use ADT75 since free samples of the IC were available.



Calibration:
This pressure sensor has a pressure port having a port diameter of 2 mm.
To measure a pressure in any vessel an outlet of the vessel is connected to this port using a 2mm tube.
*Care must be taken to ensure that no leakage exists.
A digital Manometer was used for the calibration of the pressure sensor. This was done at the Process Instrumentation Laboratory Department of Instrumentation and Control, at the College.