• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Developing an opacity

Extracts from this document...

Introduction

Developing an opacity sensor There is a huge range of different sensors in this world, designed to detect changes in temperature, size, distance and many other important factors. Their ability to do this makes them valuable for use in industry, in particular, production processes. I have chosen to develop a sensor which measures the concentration of solution, suitable for the factory production of pre-diluted fruit squashes. The sensor can control the machinery via a servo-mechanism, indicating whether more squash needs to be added. The context in which my sensor is to be used is an important consideration as it determines a suitable sensitivity and resolution. Factors to consider when designing a sensor: Sensitivity The ratio of change of output to change of input. A very sensitive sensor will give a big change of output for a small change of input. A sensor which detects very small changes of input will need to be very sensitive so these changes can be observed. Resolution The smallest change the sensor can detect in the quantity it is measuring. If you had a quantity which was displayed as 0.0076, this sensor would have quite a high resolution (depending on what it was measuring). If the last digit were fluctuating this would be the maximum resolution of the sensor as it can only just resolve a change of that magnitude - 10,000th. A cooks oven may only need a resolution of 5�C whereas a baby monitoring system requires a resolution of 0.5 - 1�C. Response time The time a sensor takes to respond to a change in input. ...read more.

Middle

Preferably, the tube would be just below the surface however this would mean moving the LDR nearer to the light source with each solution, which, as explained earlier, is unfavourable. The battery for both the lamp and LDR will be switched on and a reading taken from the voltmeter and recorded. 50 ml of solution will then be added from the second beaker to raise the level to 100ml and another reading recorded. This will be repeated to 200ml . I must also consider safety as electricity and water are a dangerous combination. I will minimise the risk of electrocution by: * Removing the beaker from on top of the lamp and away from other apparatus before adding more solution. * Turning off the power pack between additions of solution. * I will dry my hands before touching the wires and other electrical apparatus. * The voltage will be kept low which will not minimise the risk of electrocution but will minimise danger. Hypothesis: The more light falling on the LDR, the less its resistance. So as volume increases, voltage increases as less light reaches the LDR and resistance increases. As the components are in a series circuit (same current flows through variable resistor and LDR - no alternative route) the voltage across the LDR increases. This can be explained by: V=I x R If the current is 2A and resistance 0.5 ohms then V = 1 If the current is 2 A and resistance 1.5 ohms then V = 3 Predicted Results - I had to first take a reading at 50ml and then 200ml to determine a suitable range. ...read more.

Conclusion

My sensor is therefore sensitive enough to detect concentration changes of 1%. However the voltage change is not uniform, it varies between 0.06 to 0.09, a range of 0.03. As the variation in V change shows no trend, I can conclude that the relationship between volume of squash (concentration) and voltage is linear. This variation in voltage change is most likely to have been caused by small alterations in apparatus. It is unlikely to be caused by the resolution of my sensor; if the sensor was only just able to resolve voltage changes to one hundredth of a volt then the variation would only be of 100th of a volt, not 3 � 100th of a volt as can be seen in my results. By calculating an average voltage change, to eliminate the effect of changes in apparatus, I can determine the sensitivity of my sensor: (0.06 + 0.07 + 0.08 + 0.09) � 4 = 0.075 resolution only to 100th so 0.08V/1% variation in concentration However, taking into account the apparatus will affect the voltage readings, a change of 0.06 V would need to initiate the addition of more solute as this would be the minimum change for 1% concentration increase. In conclusion, I believe I have achieved my aim of creating a suitable sensor for detecting variations in squash concentration. It is sensitive enough to detect relevant concentration variations and also means that a resolution of 0.00V is sufficient. I recognise that my sensor had structural faults; the apparatus had to be constantly adjusted between readings, but with the equipment available this fault couldn't be rectified. ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Systems and Control section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Systems and Control essays

  1. Investigate the relationship between voltage and Current.

    resistor VbR A V 2 0.02 0.76 4 0.25 2.53 6 0.42 4.23 8 0.57 5.75 10 0.74 7.57 Average 10.5? resistor VbR A V 2 0.06 0.84 4 0.25 2.55 6 0.42 4.27 8 0.58 5.80 10 0.75 7.63 Readings I only took my readings up to 10 volts

  2. Water level sensor

    the position changed, I did not use the data for my investigation. For the last problem, I just used my hands to move the float to the middle of the beaker. So far, the new problem would occur, because of moving the float, the position of the float would change

  1. An electronics firm wishes to introduce a range burglar alarms. This coursework contains the ...

    None Mark combined top and front 63mm. from end (the end with the holes) and use strip bender to put 90 degree bend where marked above. 20 min. Ruler, pencil, 2mm. Polystyrene, strip bender and 90 degree jig. 30 min. I had to wait for the strip bender and then ask my teacher how to use it.

  2. The aim of this investigation is to design, build and test a sensor.

    This is shown by the levelling off of the curve. Calculating Voltage Output from 20cm Away and 60cm Away for 3 Volts Supplied Therefore, this circuit gives a LOW voltage when the LDR is in the light and a HIGH voltage when the LDR is in the shade.

  1. Create a circuit that includes a sensor, which in turn will enable me to ...

    voltage after the water was added to give the change in voltage. I concluded that it would be possible to add water in 200ml increments as the setup seemed sensitive enough to allow me to do this. [Fig.1] [Fig.2] Method: I will set up my experiment as shown in [Fig.4] and as shown in the circuit diagram [Fig.3].

  2. Build a sensor that detects air flow using an incandescent lamp to detect the ...

    To test the sensor and take down recoringsI will have to use a vacuum which blows out air. I will test it from different lengths and after doing some preliminary tests I shall decide on the different lengths for my final results.

  1. Electronics… did it change the way we are living nowadays?

    In television and video recording, variations stand for pattern of light or pictures. In radio, and sound recording the variation of current stand for different sounds, and in computer the variation may stand for numbers, letters or other bits of information.

  2. Report into Electricity Generation and Sustainable Energy

    What can you do to reduce your electrical consumption? 7. What can you do to reduce your electrical costs? Research Answers 1. Electricity can be defined by the flow of electrons through a series of conductors in the form of a closed circuit, but this definition barely touches upon what electricity actually is.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work