visitors this year: 131 A thermistor is an electronic component whose resistance changes with temperature. The voltage and current of a thermistor can be measured as the temperature changes. Sensors allow you to take...
visitors this year: 100 You can ‘see’ magnetic fields using iron filings. You can measure the strength of magnetic fields using a magnetic field sensor connected to a computer. How, for example, does that...
visitors this year: 50 In this experiment the resistance of a lamp, resistor or diode is measured as the current is varied. Voltage and current sensors make the measurements while the software plots the...
visitors this year: 41 The voltage and current in a circuit change when a capacitor charges and discharges. Computer sensors can measure these changes and software can plot a graph as fast as this...
visitors this year: 40 Batteries or electrical cells are made using different substances. There are zinc dry-cells, alkaline cells and lead-acid accumulators. When you use them, the chemicals become exhausted at different rates. So...
visitors this year: 83 Batteries are a handy source of power. You’ll know that there are different kinds of batteries, and maybe that some are good for some jobs, and some for others. But battery...
visitors this year: 177 A position sensor can be used to study this. The sensor is attached to a weight and spring assembly as shown. This can also be used to study the effects...
visitors this year: 188 The pressure in a sealed container changes with temperature. These changes can be monitored using sensors attached to the computer. A graph of pressure against temperature can be plotted as...
visitors this year: 158 Radioactive materials decay, or lose their radioactivity, in a predictable way. If you have a fast decaying source, such as Protactinium with a half life of just 72 seconds, you...
visitors this year: 34 Get two temperature sensors to measure the temperature inside and outside a window. You may find that over a long period of time it is best to record your data...
visitors this year: 92 You can use a temperature sensor to study the conduction of heat through materials. Two temperature sensors allow you to compare different materials at the same time. In this example,...
visitors this year: 47 Three plastic cups are stacked inside each other and a temperature probe placed between each cup. Before stacking the final cup hot water (take care) is poured into the middle...
visitors this year: 215 You can use a temperature sensor to study the insulating properties of materials. Two temperature sensors allow you to compare different materials at the same time. In this example two...
visitors this year: 188 When a living thing, such as yeast, respires it produces heat. It may do this in the presence or absence of oxygen. These processes are called aerobic respiration and anaerobic...
visitors this year: 263 How are plants affected by light? During photosynthesis oxygen is produced. How much photosynthesis occurs depends on how much light there is. You can measure the amount of oxygen produced...
visitors this year: 105 When seeds germinate they use energy and give off heat. To test this, you can use temperature sensors which will continuously monitor any heat produced. You will set up some...
visitors this year: 110 It’s not easy to measure how fast a plant grows. You would probably not be too keen to take measurements every few hours – and especially not overnight. There are...
visitors this year: 45 As food burns it releases energy. This energy can be used to heat up water. If you know how much water you used, and how hot it gets, you can...
visitors this year: 702 Fats, such as the fats in milk, need to be digested by your body. They are broken down into fatty acids and glycerol by an enzyme called lipase. You can...
visitors this year: 107 In the manufacture of yoghurt, bacteria turn lactose into lactic acid. The acid denatures or spoils the milk protein and sets it solid. In the process, the milk starts to...
visitors this year: 37 The speed of your pulse changes as you go about your day. It changes as you sit, walk or exercise. It is quite easy to record your pulse using the...
visitors this year: 216 Is your breathing steady while you sit restfully? How does it change when you talk? How does it change when you exercise? How quickly do you recover after exercise? To...
visitors this year: 192 Life in any aquatic habitat has to be supported by oxygen. We are all too familiar with rivers and streams where the oxygen supply has been exhausted and the river...
visitors this year: 93 Amylase catalyses the breakdown of starch into sugar. How is the activity of this enzyme affected by temperature? You can start to find out by monitoring the activity at different...
visitors this year: 150 Measuring the appearance of cloudy sulfur when we mix acid and sodium thiosulfate is a popular science teaching activity. We can change the temperature or concentration of the reagents, and...
visitors this year: 278 If you were a chemical manufacturer you would certainly be interested in finding ways to increase the rate of production. One way is to do the reaction at a higher...
visitors this year: 113 Hydrochloric acid and marble (CaCO3) react to form carbon dioxide gas. The gas can be captured and measured using a gas syringe. A position sensor can be attached to the...
visitors this year: 41 You can sense the human pulse cheaply using a sound sensor. While pulse sensors can now be found even in phones, using a sound sensor works too. Hold a sound...
visitors this year: 50 The speed of sound has been measured in so many ways but this version I saw my colleague Ian Galloway* demonstrate perfectly, impressed so I want to pass it on....
visitors this year: 171 If you’ve a couple of pH electrodes and sensors, the following is one of the most successful enzyme measurements I’ve tried. Before bothering further, connect the pH electrodes to a...
visitors this year: 124 Transpiration and a pressure sensor A sensitive barometric pressure sensor can be used to demonstrate transpiration. The picture here shows a low pressure sensor (as it was called) with a...
visitors this year: 50 An investigation with insulated and un-insulated beakers – reloaded “I bought a metal mug to carry my coffee for my daily trip to the train station. But twenty minutes down...
visitors this year: 32 Simple harmonic motion is rarely as simple as the lesson title implies. This potentiometer-based sensor measures angles as its core rotates. Attaching a ruler as shown (or hack saw blade)...
visitors this year: 384 what affects the rate of reaction? A chemical reaction can be made to go fast or slow. In this activity you will try to measure how a chemical reaction is...
visitors this year: 48 When quicklime is mixed with water an exothermic reaction takes place. A temperature sensor can collect information about the heat generated over time. Other things being equal, this reaction might...
visitors this year: 178 As acid drains into alkali the pH changes. This can be monitored using a pH sensor to produce an instant graph of pH against volume. The easy way of doing...
visitors this year: 74 As a candle burns oxygen is used and heat and water are produced. A few sensors can be used to monitor this process. A light sensor indicates when the candle...
visitors this year: 40 Might be used for measuring the variation in UV light during the day or as meter to compare sun creams and sunglasses. UV sensors can be found in ‘wearables’ like...
visitors this year: 38 Used like a wand and moved in magnetic fields. Interesting in the way it measures the unseen. Has a niche use in applications showing magnetic field changing over time or...
visitors this year: 63 The scope for electrical measurement as obviously as big as the subject itself. Data logging systems tend to measure changes over time and that suits these sensors to measuring the...
rogerfrost.com is a compendium of ideas for using technology with sciencey questions in mind. Started in 1995 to offer ideas to school science teachers, Roger Frost expanded the coverage to home automation, gadgets and sensors to measure, or understand, what’s going on around him.
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Roger Frost has been writing about technology since 1988 and this web includes articles; radio interviews with scientists and tutorials to use technology at home and the classroom.
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