Introduction to Data Logging Technology Enhanced Inquiry Based Science Education

Data-logging Process of measuring and recording data over a period of time via a data-logger and sensors. This process is controlled by software running on a computer or on a data-logger itself.

Sensors Sensors are electrical devices that measure physical quantities and convert them it into electrical (often voltage) signals.

Biology : Blood pressure, CO 2, Conductivity, Dissolved Oxygen O 2, ECG, Heart rate, Light, O 2 Gas, Relative humidity, Spirometer, Temperature … Chemistry : Conductivity, ORP, pH, Pressure, Salinity, Temperature, Turbidity, Transparency, Voltage … Many physical properties can be measured with sensors. Physics : Acceleration, Angle, Charge, Current, Distance, Force, Light, Magnetic Field, Pressure, Radiation, Sound, Temperature, Voltage …

Data-logger A data-logger converts the electrical signal generated by a sensor into a digital code, which is processed by the device itself or sent to the computer. A portable data-logger, data collection is controlled by software running on the data-logger. A data-logger connected to a computer via USB port, data collection is controlled by software running on the computer.

Data-logger Different data-loggers are available for different school levels.

Software Dedicated software, like Coach 6, running on the data-logger or on the computer, allows to: Monitor the measured data Control the process of data collection – how long and how often to measure Collect data according to the given settings Plot the collected data Analyze and process the data Store the data.

Biology Recording ECG Using the ECG sensor to record and to study the electrical activity of the heart. The heart produce electrical voltages that are measured via electrodes placed on the skin of the wrists.

Biology Measuring heart rate Using the heart rate sensor to measure heart rate. Each time that the heart contracts, blood is pumped into the arteries. The Heart Rate sensor monitors the flow of blood through the ear lobe, it shines a light through and measures the light that is transmitted.

Biology Photosynthesis Investigating processes of photosynthesis. Using the CO 2 gas sensor to monitor CO 2 gas production by green spinach leaves in dark and in different lights.

Biology Photosynthesis Monitoring photosynthesis over a longer period of time (72 h). Many sensors can be used for such investigation: O 2 gas, CO 2 gas, light, temperature, humidity.

Biology Respiration of maggots Monitoring the process of respiration by maggots. CO 2 sensor is used to monitor the level of carbon dioxide in a closed respiration chamber containing living fly maggots.

Chemistry Endothermic reactions Measuring temperature during endothermic and exothermic reactions. During the spontaneous reaction between sodium carbonate (Na 2 CO 3.10 H 2 O) and citric acid (C 6 H 8 O 7.H 2 O) a temperature decrease occurs.

Chemistry Acid base titrations Measuring the pH value during acid-base titration. As acid is added to the base, the pH gradually changes. At the equivalence point the change is very rapid. The adding of the titrant can be done automatically by controlling a step-motor burette. In this way the added volume of the titrant can be accurately determined.

Chemistry Temperature of flames Thermocouple sensor measures temperatures between -200  C and 1400  C and is used to study temperature inside flames. Temperature differences between several places in a flame can be easily demonstrated.

Chemistry Rate of reaction Observing the rate of chemical reaction by measuring the change in concentration with the Colorimeter.

Chemistry Energy content of food Determining energy content of a potato chip by measuring the heat release from its combustion. Measurement with temperature sensor placed in good thermal contact with the calorimeter. The heat can be calculated by comparing to a calibration measurement made with a standard electric lamp in the place of the burning chip.

Physics Changing of state Measuring with a temperature sensor. Observing process of changing state, from liquid to solid, during cooling of stearic acid.

Physics Make sound visible Investigating the waveforms of sound waves and sound beats. Very short (between 50 and 500 ms) and very fast ( Hz) measurements with the sound sensor make sound visible.

Physics Measuring speed of sound Determining the speed of sound in air using the echo method. The sound sensor detects the initial sound and its echo - sound reflected off the opposite end of the tube. From the known distance and traveling time the speed of sound can be calculated.

Physics Electromagnetic induction Measuring the voltage induced by a magnet falling through a coil. Investigating how the induced voltage is affected by reversing a magnet or by using magnets of different strengths. The measurement is started automatically by using triggering.

Physics Boyle’s law Investigating the relationship between the volume and the pressure of air in the syringe (Boyle’s law). The air pressure is measured with the pressure sensor and the respective value of the air volume is typed in via keyboard.

Educational benefits of data-logging Data-logger becomes an universal instrument Data-logger equipped with a selection of sensors becomes an universal measurement instrument and can be used in many different experiments. The measurement process is automatic Data collection and the presentation of the data in table and graph format are automated. This gives extra time to focus on the physical phenomena and different aspects of an experiment.

Educational benefits of data-logging Remote logging - data may be collected and stored independently of the computer This allows the collection of data in a wide variety of environments, including outdoors, and facilitates collection over long periods of time, beyond the normal scope of lessons in school. The rate of data collection is available over a wide range of frequencies Very fast and very slow rates of data collection provide new contexts for gathering data and expand students' experience of phenomena.

Educational benefits of data-logging Real-time presenting data while being collected This makes data collection an interactive process whereby direct observations may be immediately compared with the graph, encouraging thinking about the data. The accuracy of measurements and recording This is superior to manual traditional methods. The reduction of errors in taking readings This results in better quality information which potentially improves the clarity of relationships between variables.

Centre for Microcomputer Applications