BS EN 60068-3-11:2007
$167.15
Environmental testing – Supporting documentation and guidance – Calculation of uncertainty of conditions in climatic test chambers
| Published By | Publication Date | Number of Pages |
| BSI | 2007 | 38 |
Demonstrates how to estimate the uncertainty of steady-state temperature and humidity conditions in temperature and humidity chambers. Since this is inextricably linked to the methods of measurement, these are also described. This standard is equally applicable to all environmental enclosures, including rooms or laboratories. The methods used apply both to temperature chambers and combined temperature and humidity chambers. This standard is meant to help everyone using climatic test chambers. Those already familiar with uncertainty of measurement will find it useful for guidance on typical sources of uncertainty and how they should be quantified and combined. It is also intended to assist the first-time or occasional user who has little or no knowledge of the subject. To discuss uncertainty, it is important first to understand what is being measured or characterized. The calibration or characterization of the performance of a chamber is concerned with the humidity and temperature of the air in the chamber, as experienced by the item under test, at a given set point. This should not be confused with characterizing or calibrating the chamber sensor, which is a separate matter.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 8 | 1 Scope 2 Normative references |
| 9 | 3 Terms and definitions |
| 12 | 4 Concept of uncertainty 4.1 Uncertainty, error and “true value” |
| 13 | 4.2 Statements of uncertainty 4.2.1 General 4.2.2 Best estimate of the true value of the measured quantity 4.2.3 Confidence interval 4.2.4 Confidence level 4.2.5 Statement of uncertainty |
| 14 | 4.3 Combining uncertainties 5 Tolerance 6 Humidity and temperature measurement |
| 15 | 7 Methods for determining climatic test chamber uncertainties |
| 17 | 7.1 Empty chamber 7.1.1 Advantages 7.1.2 Disadvantages 7.2 Typical load 7.2.1 Advantages 7.2.2 Disadvantages |
| 18 | 7.3 Measurement of conditions in the chamber during the test 7.3.1 Advantages 7.3.2 Disadvantages 7.4 Conditions to measure |
| 19 | 7.5 Measurements required 7.5.1 Temperature 7.5.2 Humidity |
| 20 | 7.5.3 Recording procedure 7.6 Sources of uncertainty 7.6.1 Calibration uncertainties 7.6.2 Instrument uncertainties 7.6.3 Uncertainties arising at the time of the measurement 7.6.4 Uncertainty by radiation |
| 21 | 7.6.5 Additional uncertainties 7.7 Essential contributions of uncertainty 7.7.1 Reference instrument calibration uncertainty 7.7.2 Reference instrument drift 7.7.3 Resolution 7.7.4 Temperature effects |
| 22 | 7.7.5 Hysteresis 7.7.6 Measurement repeatability 7.7.7 Fluctuations 7.7.8 Gradients |
| 23 | 7.7.9 Additional uncertainties when calibrating an empty chamber or a chamber with a typical load |
| 25 | 8 Estimation of uncertainty components and their combination 9 Overall uncertainty of temperature measurement 9.1 General |
| 27 | 9.2 Further considerations 10 Overall uncertainty of relative humidity measurement |
| 28 | 10.1 Uncertainty of temperature measurement at each sensor point 10.2 Uncertainty of the relative humidity measurement |
| 31 | 11 Anomalous data and presentation of results 11.1 Average case analysis 11.2 Worst case analysis |
