Education and Manpower Bureau
Using Datalogger in the Teaching of Physics


Introduction of datalogger

What is a datalogger?

A datalogger is an electronic instrument that records measurements of temperature, relative humidity, light intensity, voltage, pressure, on/off and open/closed state changes etc. over time. Typically, dataloggers are small, battery-powered devices that are equipped with a microprocessor, memory for data storage and sensors. Most dataloggers interface with a personal computer and utilise software to activate the logger and view/analyse the collected data.

Data-logging implies data collection with storage for later data processing. A data-logging system has three main components: an interface to link to a computer, sensors and software. While planning to purchase a data-logging system, the following points need to be considered as well: purchasing strategy, organising resources, features and prices.

How does a datalogger work?

The datalogger is first connected to a personal computer. Specific software is then used to select logging parameters (sampling intervals, start time, etc.) and initiate the logger. The logger records each measurement and stores it in memory along with the time and date. The logger is then reconnected to the personal computer and the software is used again to readout the data and view the measurements as a graph or table showing the profile over time. The data collected can be exported to a spreadsheet for further manipulation.


Data-logging interfaces connect to computers and can have sensors plugged into them. They convert the readings which they derive from the sensors into data which the computer can use. They convert continuous variable signals from the sensors to numbers using a circuit called an analogue-to-digital converter. These numbers are converted into real values and displayed by a computer programme. Some data-logging interfaces - called dataloggers - have their own memory and power supply and can record data without an attached computer.

A datalogger is a self-contained serial port interface which has its own power supply and memory to allow it to collect and store data over time. It can be connected to different types of computers to transfer data and instructions.

Some dataloggers must be programmed from the computer with specific instructions about what and when to record, and are then disconnected from the computer to carry them out. DataLoggers can be activated by the press of a button and begin recording with whatever sensors are plugged in, continuing to do so until they are deactivated. Some have small display screens to display data in graphical form as it is collected, a feature which enables students to see what is happening (and to reassure them that the device is working!). Some dataloggers can hold more than one set of data in memory at the same time and all can transfer their data to a host computer for analysis.

Battery life can be a problem. Dataloggers can be programmed to record data for weeks - as long as the batteries last (half as long as the manufacturers claim is a good rule of thumb). Use a mains power supply adaptor, if you can, to ensure that you'll have some data worth analysing after a long recording.

Predictably, the more features a datalogger has, the more it costs. It is worth considering whether you have a real need for all the advanced features of an expensive datalogger compared with a mid-priced serial data-logging interface.

Datalogger interface:

  Brand Product (Click for detail information)
  EasySense Advanced

EasySense Fast

  Griffin & George
  DataMeter 1000



  PASCO   ScienceWorkshop 750 Interface

ScienceWorkshop 500 Interface

  Philip Harris




Almost all data-logging interfaces have their own specially written software either provided for free with the interface or at an extra cost. Obviously, you will need to ensure that the software is available for your computer before you buy a data-logging system and be wary of a manufacturer who tells you that the version you require will be available 'shortly' - that could mean anything from four weeks to eighteen months!

In the special case of analogue port interfaces, most software written to work with one will work with others. However, each will contain calibration tables which are specific to a particular sensor, so ensure that you have software which will give accurate readings with the sensors you are using.

Bundle software:

  Software Features Download
  DataStudio Software (PASCO)
All-in-one software solution that collects, displays, stores, and analyses scientific data using a computer.
  Specification PDF
Flexible, easy-to-learn technology that lets students learn by asking and testing "what if" questions that reveal scientific principles.

  Demo Software
  Sensing Science Laboratory Workroom (DATA HARVERST)
Contains Meters, Timer and Graph data capture and analysis programme.
  Demo Software
The workroom includes an example worksheet.

The worksheets are written in HTML format which can simply load and print.
  Manual PDF
Further instructions are given to easily write worksheets that will also interact to set up the data-logging parameters.

  Insight2 (LogIT)
Sensors are automatically identified and displayed.

  Demo Software
Logs real-time from LogIT SL, LIVE or DataMeter at a rate of every 0.1 seconds for 60 seconds up to every 900 seconds for 7 days.

Timing mode for time, speed, acceleration, velocity, kinetic energy, etc.

  Specification PDF
Loads remote data from DataMeter and LogIT SL.

Resizable graph, table, bars and digits display.

Zoom, print, save or export data.

Compare data channels from different experiments.

Comprehensive tools for advanced analysis.

Keyboard control of cursors.

Manual data entry from keyboard for modelling.

Intelligent conversion of units for time axis.

Both Programme Guide & Teachers Manuals supplied.

Supports all LogIT family dataloggers.

Supports single channel control (for use with output devices such as the LogIT Control Relay).

Simple recalibration of some sensors.

Conditional start and overlaying of results.

Insight2 OEM (LogIT)
Designed for use across all age ranges and is a self contained program, rather than having separate programs, which comprises the main functions of data logging, timing and control.

  Demo Software
Can display results in graph, bars,table or notes form and export data in various formats including the ability to cut and paste directly into Excel spreadsheets.

  Specification PDF
Able to read SID files, as produced by LogIT DOS software and Insight, and LOG files, as created by Psion 3 series/Pocket Book logging software and LogIT Arc software.

The log rate can be left on automatic (AutoLog) or set by the user from 500 readings per second (depending
on computer system and data logger) to 1 per hour. A maximum of 5000 readings per sensor can be stored (system dependent).

Snapshot logging is supported and readings can be taken on a key press, button click or menu selection. Up to 5000 readings per sensor (system dependent) can be stored.

Real time timing provides direct measurement of time interval, speed, velocity, acceleration, momentum, kinetic energy, simple harmonic motion period.The timing function measures with 64 microsecond resolution from a few milliseconds to one hour and supports up to three sensors. Most features and options available during timing including table display.

Feedback control is supported at rates up to about 4 per second (see technical information) and utilises the current range of Microsense® control products - SwitchIT (4 channel relay), Control relay, buzzer and LED.

manually entered data together with sensor data

flexible overlay of repeat experiments

counting option for digital sensors (also some loggers have other measurement types eg. period)

scale options available (eg. for temperature you can have °C,
°F, or °K)

The graph can be printed easily, to any Windows supported graphics printer, and will be output as it is configured / displayed on the screen




   Data Harvest Light Gate / Pendulum / Timing Mats

Conductivity Adaptor and Electrode / Magnetic Field / Push Button Switch / Voltage and Current

  Electricity & Mechanism
Heart Rate Monitor

  Optics & Wave
Barometric Pressure / Gauge Pressure / Geiger-Muller / Humidity / Light Level / Sound Level / Temperature / Thermaflow / Thermocople Adaptor

  Heat & Energy
 Pasco Acceleration / Barometer / BNC Adapter / Cable, DIN / Cable, Phone Jack Extender / Charge / Colorimeter / Conductivity / Current / Dissolved Oxygen / EKG / Flow Rate / Force / Force, Economy / Free Fall Adapter / G-M tube / Heart Rate / Humidity, Relative / Infrared / Ion Probes / Ion-selective Electrode Amplifier Box / Laser Switch / Light / Light, High-sensitivity / Magnetic Field / Motion Sensor II / Nuclear / Nuclear, Beta Gamma / pH / Photogate/ Accessory / Photogate, Pulley System / Pressure Sensor -- Absolute / Pressure Sensor -- Low / Respiration Rate / Rotary Motion / Sound / Temperature / Temperature, High Accuracy / Temperature, High Type K Probe / Temperature with Type K Thermocouple Probe / Thermistor / Thermocline / Time of Flight Accessory / UVA Light / Voltage

 LogIT Microsense® Movement & Position Sensor / Microsense® Push Switch

1 Volt Sensor Adapter / Designer Sensor Set / Instrument Adapter / 100mV Signal Adapter / Ohaus Scout and Fisher Balance Adapter / Serial Balance Adapter / pH Adapter / Adjustable pH Adapter / Redox Adapter / Conductivity Probe Set / Microsense® Magnetic Field Sensor / Microsense® Magnetic Switch

  Electricity & Mechanism
  Heart Receiver / Pulse Monitor / General Light Level Sensor / Light sensor with Lens / LUX Sensor / SPX LUX Sensor / Microsense® Light Gate / Microsense® Light Switch / Microsense® Infrared Source / Microsense® Reflective Light Switch / Microsense® Ultrasonic Ranger

  Optics & Wave
Standard Humidity Sensors / HumiPro Humidity Sensor / Sound Level Sensor / The Microsense® Air Pressure Sensor / ProTemp Temperature Sensor / HiTemp Temperature Sensor / K-Type Thermocouple Adapter

  Heat & Energy

Pucharing Strategy

Data-logging interfaces have developed quickly over the last five years to an extent that today's devices are generally reliable and easy to use and should give a good number of years of service. In terms of functionality there is not a great deal to choose between devices in equivalent categories, but do note which features you get for your money. You will, of course, want to make the best of your investment in data-logging equipment by getting as much productive use from it as possible.

Decide, first of all, where the equipment will be used. For use in the science lab, a serial-port interface will probably suit you; if you want to carry out data-logging away from a computer or if the technology department is involved in computer control, then you may consider a datalogger or a measurement and control interface. In either case, ensure that there is good software to support the computers which are in your school now and may be in the future.

You will be buying a data-logging system, not only a data-logging interface, but also a set of sensors, a computer connecting lead and software. The total cost needs to be taken into account. Ensure that your chosen system has the range of sensors which you will require; think in terms of a basic set of frequently-used sensors per interface plus one or two of the more expensive sensors. Most manufacturers offer some sort of starter kit.

Questions to ask before purchasing a data-logging system:
¡P Why should data-logging systems be used?
¡P Where will data-logging be used to enhance scientific learning?
¡P What teaching styles are best suited to using data-logging?
¡P Where will data-logging fit into the students' development of IT capabilities?
¡P How will staff be trained to use the system?
¡P What do you have already?
¡P Which sensors should be included?
¡P Who will organise the equipment for each lesson and who will maintain the equipment?
¡P What provisions will need to be made for maintenance?
¡P How will the kit be stored?

As with any other piece of apparatus, data-logging systems will need to be stored securely and properly maintained, but they also present their own problems. A dozen or so sensors, each with a 60cm cable, one or two connecting cables, a power supply and a mains cable can get themselves into quite a tangle. A plentiful supply of elastic bands is certainly called for when they are being packed away.

In the classroom, experience has shown that a data-logging system is best stored as a kit with an accompanying checklist for students to consult when they pack up. Students who have not used the equipment before may benefit from labelled diagrams of the sensors on the checklist. On some occasions, perhaps during an introductory session, you will want students to set up their own data-logging apparatus - an important contribution to their developing IT capability. At other times you may want to have a number of activities already set up so that students can have maximum lesson time to carry out investigations. In the latter case you may need to rely on a technician's expertise.

All staff who will use the equipment will need time to become familiar with the system they are using. In particular, the software may have useful advanced features which the students will not be aware of or able to use unless their teacher points them out.

Features to consider:
¡E Good design - sturdy, safe and reliable
¡E Accurate sensors
¡E Quality software - easy to use with good analysis facilities
¡E Compatibility with school computers - existing and planned
¡E Self-identifying sensors
¡E Warranty period, repair arrangements and turnaround
¡E A telephone help line
¡E Battery life
¡E Maximum recording time on batteries
¡E Internal memory - number of data sets that can be stored
¡E Size and portability

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