measure pulse with a sound sensor
visitors this year: 50 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...
measure the speed of sound
visitors this year: 74 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....
measure lipase enzyme activity
visitors this year: 348 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...
plant transpiration using a pressure sensor
visitors this year: 174 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...
compare insulated drink beakers
visitors this year: 98 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...
simple harmonic motion
visitors this year: 48 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)...
rates of reaction
visitors this year: 546 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...
exothermic reactions
visitors this year: 88 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...
acid-base titration
visitors this year: 251 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...
combustion – burning a candle
visitors this year: 148 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...
ultra-violet sensor
visitors this year: 55 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...
magnetic field – Hall probe
visitors this year: 46 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...
voltage & current sensors
visitors this year: 106 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...
radioactivity – Geiger-Muller
visitors this year: 58 Uses a separate Geiger probe to measure radioactive counts or count rate. Most useful are those that show the count rate at a point in time – with a fast...
position or angle sensor
visitors this year: 83 This sensor allows superb and easy to do investigations into the swing of a pendulum leading on to studies of harmonic motion and damping. (See several examples nearby). It allows...
oxygen and pH sensors
visitors this year: 98 oxygen sensor Sensor is used in conjunction with an oxygen electrode. Good for demonstrations where you monitor photosynthesis, fermentation or where you re-breathe the air in plastic bag. Before you...
humidity sensor
visitors this year: 56 A less widely used sensor that nevertheless shows interesting results when monitoring environments over time. Place one in a polythene bag with your hand, or a plant and see how...
conductivity sensor
visitors this year: 49 This sensor is used in conjunction with a conductivity cell. It tends to used as a stand-alone meter to measure salinity or total dissolved solids in water. Offers some enhancement...
balance sensor
visitors this year: 47 Balances and interfaces have for a long time tried to find a common language for talking to each other. A few systems found this and offered a balance adapter that...
pressure sensor
visitors this year: 52 A surprisingly useful sensor which is usually on the expensive side. They come in various ranges and while no single range handles all uses you can settle on a mid...
breathing sensor, ecg & pulse
visitors this year: 83 A dedicated device that shows the breathing rate or in some designs, the breathing movements. The latter types are more interesting as they show the depth of breathing too. However,...
sound sensor & microphone
visitors this year: 119 sound sensor Sound sensors tend to find their use as stand alone noise meters but this misses some interesting uses where sound level changes over time. Just using it as...
light sensor & colorimeter
visitors this year: 206 Often used elaborately to produce a makeshift colorimeter, the light is very useful for many biology and chemistry experiments on rates of reactions. As monochromatic light is less important with...
heat flow sensor
visitors this year: 80 Used to measure the flow and direction of heat through clothing or building materials. It contains countless thermistors and unlike a temperature sensor, provides readings as Watts/m2. While its classroom...
distance sensor or sonar ranger
visitors this year: 118 These distance or motion sensors use sound reflected from an object to detect changes in its position. Most designs were based on the sensor developed as the range finder for...
accelerometer, dynamics pulley
visitors this year: 122 Accelerometers contain the tiny chip sensors often used as triggers for car air bags. You can take one of these sensors into a lift, fix one to a dynamics trolley...
light gates and switches
visitors this year: 247 These are digital switches that record a time when triggered by say, a dynamics trolley or a card. When you enter parameters like distance or mass into the software, velocity,...
