ISO 7730 - Thermal environment

Swema equipment for the measurement of Moderate Thermal Environments complies with the standards:
ISO 7726 – Thermal environments – Instruments and methods for measuring physical quantities
ISO 7730 – Ergonomics of the thermal environment – Analytical determination and interpretation of satisfaction of thermal environment using calculation of the PMV and PPD indices and local thermal comfort criteria.ISO 7730 measurements Many test data shows that it is possible, with six variables, to determine how warm or cold a person feels:
Measured values: Air temperature, Air velocity, Air humidity, Mean radiant temperature, Personal activity, Clothing insulation.
Thermal comfort is defined as that condition of mind which expresses satisfaction with the thermal environment. Due to individual differences, it is impossible to find a thermal environment that will satisfy everybody. The goal must be to get as few unsatisfied people as possible.
According to ISO 7730 are there three indices to describe dissatisfaction (or satisfaction) rate in thermal environment, PMV, PPD and DR:
PMV: Predicted Mean Vote, is the sensation of body heat, from +3 (hot) to +1 (slightly warm) and from -1 (slightly cold) to -3 (cold).
PPD: Predicted Percentage Dissatisfied, is the percentage of people dissatisfied with the thermal environment.
DR: Draught Rate, is the percentage of people predicted to be bothered by draught. Draught is an unwanted local cooling of the body caused by air movements.