Section 6 | Thermometry (TC and Hygrometry) Standards Section

Overview

Capabilities


 

  • Calibration and measurement capabilities achieved in the 1st 6 months of 2011
    • using rehabilitated equipment
    • using in-house and homegrown talent, expertise and technology
  • Calibration and measurement work supported by ISO 17025 compliant
    • technical procedures and work instructions
    • Certificate of Calibration

Calibration


 

Calibration of Temperature Controlled Enclosures

  • 20 °C to 250 °C
  • procedure patterned after
  • involves measurement of:
    • air temperature at several locations
    • temperature uniformity
    • temperature stability – 30 measurements at 1 minute interval
    • chamber temperature in unloaded state (empty)
  • measurements performed using a 12-channel scanning thermometer with type K thermocouples
    • measurement data acquired by computer
  • -measurements traceable to LIGT, DT and IPRT Temperature Standards Section of the NML Philippines
  • 0.7 °C best uncertainty; usually bigger due to enclosure characteristics

 

Calibration of Thermo-Hygrometers

  • 40 %RH to 80 %RH at 23 °C
  • performed in a temperature and humidity controlled chamber
    • reservoir of water under the chamber workspace is heated or cooled to generate water vapor which is then mixed with temperature conditioned air to humidify the chamber workspace
    • RTDs with digital indicators are used to measure the dry and wet bulb temperatures that serve to establish reference humidity values
  • temperature-humidity conversions performed according to Temperature and Humidity Measurements: Book 3 – NML, CSIRO Australia
  • 1.7 % RH best uncertainty; about 3 x better than most hygrometers submitted for calibration

 

Calibration of Thermocouples

  • 500 °C to 1000 °C
  • performed using the comparison method in a 3-zone temperature controlled furnace
    • emf of reference thermocouple and thermocouple under calibration are measured using a high resolution nanovoltmeter
    • measurement data acquired by computer for further processing
  • reference temperature values derived from a standard Type S Thermocouple calibrated at KRISS, Korea
  • type R thermocouples are calibrated against the Type S Thermocouple and are used as working standards for general calibration work:
    • calibration of customer thermocouples and own thermocouples

Traceability

Traceability

thermocouple hygrometer Enclosure

Services

Services


 

Instrument / Equipment

Range

Service Offered

Method

Digital Thermo-Hygrometer

RH: 40% and 60% at 23 oC

Temperature: 20 oC, 25 oC  and 30 oC

Calibration

Comparison

Themocouple

Up to 1000  oC

Enclosure (Oven, Incubator, Autoclave, Water Bath, Refrigerator, Freezer)

-30  oC to 250  oC

Calibration

Comparison

Furnace

Up to 1000  oC