Mercury Thermometer Reading Error
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care and maintenance of the shelter is described in NAVAIR 50-30FR-518, Operation and Maintenance, Standard Air, Maximum and Minimum types of instrument error Thermometers, Townsend Support, Sling and Rotor Psychrometers, and Instrument Shelters.
Possible Sources Of Error In Measurement
The routine care of the shelter includes keeping it free of dirt and debris
Instrumental Error Definition
and oiling the door hinges. Backup equipment usually kept inside the shelter includes the rotor, sling or electric psychrometers, and maximum and minimum
Instrumental Error Examples
thermometers mounted on a Townsend support. When the temperature is above freezing, a bottle of distilled water is also included for the psychrometers. REVIEW QUESTIONS Q9. What is the purpose of the ML-41 instrument shelter? Q10. What tasks are included in the routine care for the instrument shelter? sources of error in chemistry lab experiment THERMOMETERS LEARNING OBJECTIVES: Describe the char- acteristics of liquid-in-glass thermometers. Explain how to properly read a thermometer. Identify three types of liquid-in-glass thermometers. Liquid-in-glass thermometers, such as alcohol or mercury thermometers, are found throughout the Navy and Marine Corps in various configurations. Some are simply closed glass tubes mounted on a graduated cardboard, plastic, or metal backing, and others have the graduations etched into the glass. For meteorological and oceanographic readings, calibrated thermometers with the graduations permanently etched into the glass are recommended, since they are considered the most accurate. In meteorology and oceanography, liquid-in-glass thermometers are used in the rotor psychrometer, the sling psychrometer, electric psychrometers, and as simple thermometers for measuring seawater temperature by the bucket method. The maximum and minimum thermometers found in the instrument shelter are special types of liquid-in-glass thermometers. Both NAVMETOCCOMINST 3141.2 and NA
of Accuracy Accuracy depends on the instrument you are measuring with. But as a general rule: The degree of accuracy is half a unit each side of the unit of measure Examples: When your instrument measures in "1"s then any value thermometer error between 6½ and 7½ is measured as "7" When your instrument measures in "2"s then calibration error definition any value between 7 and 9 is measured as "8" Plus or Minus We can show the error using the "Plus or Minus" common error in calibration sign: ± When the value could be between 6½ and 7½ 7 ±0.5 The error is ±0.5 When the value could be between 7 and 9 8 ±1 The error is ±1 Example: a fence is measured http://meteorologytraining.tpub.com/14269/css/14269_91.htm as 12.5 meters long, accurate to 0.1 of a meter Accurate to 0.1 m means it could be up to 0.05 m either way: Length = 12.5 ±0.05 m So it could really be anywhere between 12.45 m and 12.55 m long. Absolute, Relative and Percentage Error The Absolute Error is the difference between the actual and measured value But ... when measuring we don't know the actual value! So we use the maximum possible error. In https://www.mathsisfun.com/measure/error-measurement.html the example above the Absolute Error is 0.05 m What happened to the ± ... ? Well, we just want the size (the absolute value) of the difference. The Relative Error is the Absolute Error divided by the actual measurement. We don't know the actual measurement, so the best we can do is use the measured value: Relative Error = Absolute Error Measured Value The Percentage Error is the Relative Error shown as a percentage (see Percentage Error). Let us see them in an example: Example: fence (continued) Length = 12.5 ±0.05 m So: Absolute Error = 0.05 m And: Relative Error = 0.05 m = 0.004 12.5 m And: Percentage Error = 0.4% More examples: Example: The thermometer measures to the nearest 2 degrees. The temperature was measured as 38° C The temperature could be up to 1° either side of 38° (i.e. between 37° and 39°) Temperature = 38 ±1° So: Absolute Error = 1° And: Relative Error = 1° = 0.0263... 38° And: Percentage Error = 2.63...% Example: You measure the plant to be 80 cm high (to the nearest cm) This means you could be up to 0.5 cm wrong (the plant could be between 79.5 and 80.5 cm high) Height = 80 ±0.5 cm So: Absolute Error = 0.5 cm And: Relative Error = 0.5 cm
Ruskin University University of the Arts London (UAL) Aston University Bangor University University of Bath Bath http://www.thestudentroom.co.uk/showthread.php?t=848618 Spa University University of Bedfordshire University of Birmingham Birmingham City University University http://web.stanford.edu/group/csp/cs21/calibration.html of Bolton Bournemouth University BPP University University of Bradford University of Brighton University of Bristol Brunel University University of Buckingham Buckinghamshire New University University of Cambridge Canterbury Christ Church University Cardiff Metropolitan University Cardiff University University of Central Lancashire (UCLan) University of Chester University of Chichester error in City University London Coventry University University of Cumbria De Montfort University University of Derby University of Dundee Durham University University of East Anglia (UEA) University of East London Edge Hill University University of Edinburgh Edinburgh Napier University University of Essex University of Exeter Falmouth University University of Glasgow Glasgow Caledonian University University of Gloucestershire Glynd?r University Goldsmiths sources of error University University of Greenwich Heriot-Watt University University of Hertfordshire University of Huddersfield University of Hull Imperial College, London Keele University University of Kent King's College London Kingston University Lancaster University University of Leeds Leeds Metropolitan University Leeds Trinity University University of Leicester University of Lincoln University of Liverpool Liverpool Hope University Liverpool John Moores University London Metropolitan University London School of Economics London South Bank University Loughborough University University of Manchester Manchester Metropolitan University (MMU) Middlesex University University of Newcastle New College of the Humanities University of Northampton Northumbria University University of Nottingham Nottingham Trent University Open University University of Oxford Oxford Brookes University University of Plymouth University of Portsmouth Queen Margaret University Queen Mary, University of London Queen's University Belfast University of Reading Robert Gordon University University of Roehampton Royal Holloway University of Salford University of Sheffield Sheffield Hallam University SOAS, University of London University of South Wales University of Southampton Southampton Solent University St Andrews University University of St Mark & St John (Marjon) Staffordshire University University of Stirling
with multi-digit electronic display, give the illusion of accuracy. However, knowledge of true temperature -- the real concern of measurement accuracy -- is only indirectly related to sensitivity or precision. To assure temperature accuracy, it is necessary to maintain a temperature reference standards capability. this must include equipment and procedures that permit calibration of operating devices with temperature standards in a way that insures minimum uncertainty. For most requirements the creation and maintenance of such capability is neither expensive or difficult, but lack of understanding often results in expense and inaccuracy. Equipment and procedures are discussed that permit calibration with confidence at three levels of accuracy; an uncertainty level of +/- 1.0 degrees Celsius, +/- 0.1 degrees Celsius, and +/- 0.01 degrees Celsius, respectively. Subject index: Calibration methods, general. I. INTRODUCTION This paper outlines temperature instrument calibration fundamentals that apply to "daily use" conditions in laboratory and industry. In style, language, and content, therefore, it differs from the majority of papers on temperature measurement. Most technical papers are written to advance knowledge in a given field, and are written primarily to benefit the few working actively in, and are most familiar with, that field. In contrast, this paper is written to restore to general understanding a knowledge of long-standing calibration fundamentals that are familiar to experienced professionals in the field, but are not generally understood by many who have a "need to know." The task of assuring accuracy in temperature measurement is critically important. Safety or health would be compromised, equipment damaged or product wasted in many processes if the temperature were incorrect. And no matter how precise the measurement or careful the operator, if the device is not calibrated correctly, the result is wrong. II. DEFINITION OF TERMS The assurance of temperature accuracy begins with an understanding of four key concepts: "Accuracy," "Precision," "Reference" and "Standards," and the relationship between these terms: "Precision" in temperature measurement has to do with detecting very sm