Welcome to the
Temparature and Humidity section of NMISA
NMISA's Temperature & Humidity Section has internationally recognised expertise and facilities aimed at improving the practical measurement of temperature and humidity. We help establish and maintain the International Temperature Scale of 1990, ITS-90. For the safe and effective operation of industrial processes, accurate measurement of temperature and Humidity is crucial. We support industrial measurements through a wide range of activities including research, industrial partnerships, consultation and training.
We support industrial measurements through a wide range of activities including research, industrial partnerships, consultation and training. We offer calibrations against the South African National Standards that are validated through international comparisons. We provide cost-effective, impartial, quality assured solutions: from everyday measurements to those at the extremes of sensing technology, such as temperatures above 2000 °C, or humidity in an extreme range. We work with a variety of sectors including aerospace, manufacturing, space, medical and pharmaceutical
- The kelvin, unit of thermodynamic temperature, is the fraction 1/273,16 of the thermodynamic temperature of the triple point of water. The triple point of water has the value of 0,01 °C or 273,16 K.
- Relative humidity (RH) is a ratio, expressed in percent, of the amount of atmospheric moisture present relative to the amount that would be present if the air were saturated at the same temperature
The Section offers measurement, calibration, training and consultation services as listed below:
- Calibration of contact thermometers from -196 °C to 1555 °C:
- platinum resistance thermometers (PRTs) can be calibrated from -196 °C to 660 °C (for quartz-sheathed standard PRTs) or 550 °C (for other PRTs),
- thermistors from 0 °C to 60 °C,
- thermocouples from -80 °C to 1555 °C and
- liquid-in-glass thermometers from -25 °C to 280 °C.
- Calibration of infrared radiation thermometers from 0 °C to 1600 °C and blackbody radiation sources from 0 °C to 2000 °C.
- Traceability for contact thermometry is obtained from thermometric fixed point cells from the triple point of argon (Ar) (-189.344 2 °C) to the freezing point of copper (1084.62 °C). (Pt-Rh thermocouples are calibrated at the melting point of palladium (1553.5 °C) using the wire-bridge method
- Development of calibration methods and transfer traceability to industry and African NMIs.
- Dissemination of temperature scales by calibration of temperature sensors.
- Provide a link between the African region and the rest of the world's NMIs through comparison measurements in temperature and humidity.
- Fixed points calibration of standard platinum resistance thermometers from Ar to Al points.
- Calibration of other contact thermometers in the temperature range from -80 °C to 1600 °C.
- Calibration of surface thermometers in the temperature range from -0 °C to 450 °C.
- Calibration of radiation thermometers and blackbody radiation sources from 0 °C to 2000 °C.
- Calibration of hygrometers, saturated salt solution and humidity related measuring equipment from 5 %rh to 95 %rh.
- Calibration of dewpoint meters from -75 °C to +20 °C.
- Traceability for radiation thermometry is obtained from contact thermometers up to 500 °C and from a spectrally characterised monochromatic radiation thermometer calibrated at the freezing point of silver (961.78 °C) or copper (1084.62 °C) from 600 °C.
- Development of temperature measurement solutions for industry such as electrical simulation, mapping and hysteresis analysis.
- Temperature and Humidity metrology practical training to industry and African national metrology institutes.
- Provide training through internships and bursary programmes.
- Supports fair trade, by underpinning an internationally respected measurement infrastructure in South Africa.
- Supports Environmental, Health & Safety regulation, in those areas (e.g., validation of sterilising autoclaves, measurement of heat stress) where accurate temperature measurement is required
- Improvement of primary traceability for contact thermometry
Analysis of stray thermal exchanges in triple point of water (TPW) realisation
Development and characterization of the humidity generator for primary humidity measurements
The national measurement traceability for ear radiation thermometers
The national measurement traceability for water activity meters
|Dr Nonhlanhla Precious Cele||Section Head|
|Ms Dorothy Segatibe||Honours Bursar|
|Mr Tshifhiwa Madiba||Senior Scientist|
|Ms Regina Mnguni||Metrologist|
|Dr Efrem Ejigu||Scientist/Engineer|
|Mr Sven du Clou||Engineer|
Technical Advisory Forum on the 22nd of November 2017.