What is data logger system

A data logger system is a device or a set of devices used to automatically collect, record, and store data from various sensors, instruments or sources over a period of time. It is commonly employed in scientific, industrial, environmental, and research applications where monitoring and recording data at regular intervals or continuously is necessary. The data can be anything which includes voltage, current, temperature, strain, pressure, load, power, resistance, event or state etc.

The key components of a data logger system include sensors/instruments, data logger unit, memory storage, built-in-clocks or timing sources, communication interfaces (e.g. USB, wifi, ethernet, cellular networks) and software tools. Most of the data loggers use digital digitizer for data acquisition purpose.

As mentioned in the fig-1 data logging system composed of sensors, data logging hardware and data logging software. Sensors are nothing but transducers which convert signal from one form to the other form. Depending upon the requirement there will be one sensor or multiple sensors. This results into single channel or multichannel data logger. Data logging hadware takes the data from the sensor output and stores the same into memory for further analysis or processing or for future use. It also provides the data to data logging software for the display and analysis purpose. Due to increase in the demands of various plots and measurements, it is essential to develop applications which analyze and plots the data in the form user can interpret. This goal is achieved with the use of data logging software based applications.

Types of data logger

Depending upon data logging software need data loggers are of two types viz. PC based data logger and standalone data logger. Further there will be requirement to monitor single channel or multiple channels or combination of both along with mixed data formats. Based on this, data loggers are further categorized into single channel data loggers, multichannel data loggers and modular data logging system.

Recently released data logger from Delphin technology Expert Key 100 M is compact mobile measuring system. It is equipped with 14 analog and 8 digital channel inputs. The equipment provides connectivity for sensors, actuators, thermocouples as well as RTD sensors. WLAN AP feature is also incorporate in the data logger so that data exchange can be possible from the equipment to the tablet or PC via WiFi link. The other wired communication interfaces supported are USB and Ethernet. The same is depicted in the fig-2.

Data logging software

As mentioned above data logging software are the applications which directly run on the data logger hardware or it will run on the PC connected with the data logger hardware or equipment. Due to changing need of the customers and increase in demand for multiple channels have led to development of data logging applications. PC based data loggers are ideal for such high efficiency applications as they can utilize vast processing and memory resources available in the PC. Data logging softwares are usually build using Labview, .NET or any other programming languages as needed. Driver for the communication interface also is required to be implemented. Various interfaces are available such as TCP/IP, CAN, USB etc.

Data logger manufacturers

Depending on the parameters to be logged and number of channels data loggers have been developed. Following list mentions few of the data logger manufacturers.

•  MadgeTech is one of the reputed company which builds data loggers for various applications. Madgetech manufactures loggers for temperature, humidity, pressure, motion, pulse/event/state, current, voltage, shock, water level, wind, pH, bridge strain, carbon dioxide etc. They have wired data loggers as well as wireless data loggers.

•  Delphin Technology manufactures data logger hardware and software along with interfaces/drivers. They are developed for GPS data acquisition, measurement data analysis, mobile data acquisition, de-centralized data acquisition etc.

•  OMEGA Engineering Inc. is into manufacturing of process measurement and control equipments. The data loggers from OMEGA include temperature & humidity loggers, voltage and current data loggers, pressure, strain & shock loggers, pH, flow & level data loggers, AC, power & speciality loggers and multi channel programmable data loggers etc. OMEGA manufacturers both ethernet and wireless loggers.

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