Laboratory
TEMPERATURE
PORTUGUESE INSTITUTE FOR QUALITY
FIELD OF ACTIVITY
LNM
Cell for realization of the Triple point
of the water
Realization of the triple point of
argon
Furnace with Freezing Point of
copper
The Temperature Laboratory is responsible for the development of the national standards of
temperature and relative humidity and has the following duties:
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

SI UNIT
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

The realization of the International Temperature Scale of 1990 (ITS90) on the fixed points
between the triple point of argon (-189,3442 °C) and the freezing point of silver (961,78 °C);
The realization too the ITS90 based on Planck radiation, with the freezing point of copper
(1084,62 °C);
To assure the traceability on Temperature measurements on the measuring interval from –
190 °C to 2500 °C;
Calibrate reference standards of secondary laboratories, accredited laboratories and industry;
Participate and coordinate interlaboratorial comparisons;
Technical support to the legal metrology.
International System Base Unit of Temperature (T )
kelvin (K) defined as:
The fraction 1 / 273,16 of thermodynamic temperature of the triple point of water
Derived unit of the International System of the temperature quantity (t ):
degree Celsius (ºC) defined by the equation:
t = T - T0 , where T0 = 273,15 K is the ice point. The unit of Celsius temperature unity is by definition
equal in magnitude to the kelvin.
The unit of Relative Humidity quantity (UW ) with respect to water:
Symbol (%) defined as follows:
The ratio of the actual vapour pressure (e) to the saturation vapour pressure (eW) over a plane liquid
water surface at the same temperature t (ºC), expressed as percentage. This is commonly understood
when the term “X percent relative humidity” is used.
TRACEABILITY
UW 
e
 100
eW
The traceability to SI units is achieved through the realization of the Fixed Point of EIT90 and appropriate
resistance standards.
AVAILABLE SERVICES
Calibration
EQUIPMENT
Contact Thermometry
Thermometers
Temperature Sensors
Standard Platinum Resistance
Thermometers
Comparison at stirred liquid bath
Contact Thermometry
Thermometers
Temperature Sensors
Noble -metal thermocouples Type
S and R
Comparison at heat pipe
Contact Thermometry
Liquid-in-glass thermometers
Comparison at stirred liquid bath
Non-contact Temperature
Radiation thermometers
Optical pyrometers
Measuring instruments of relative
humidity
Platinum Resistance Thermometers
Noble metal thermocouples
Optical pyrometers
RANGE
-75 ºC a 0 ºC
0ºC a 20 ºC
20 ºC a 50 ºC
50 ºC a 100 ºC
100 ºC a 200 ºC
300 º C a 450 ºC
0 º a 300 ºC
300 ºC a 600 ºC
600 º C a 900 ºC
UNCERTAINTY
0,01 ºC
0,005 ºC
0,007 ºC
0,010 ºC
0,020 ºC
0,035 ºC
0,4 ºC
0,5 ºC
0,7 ºC
900 ºC a 1050 ºC
1,0 ºC
-40 ºC a 0 ºC
0ºC a 50 ºC
50 ºC a 100 ºC
100 ºC a 200 ºC
200 ºC a 300 º C
300 º C a 450 ºC
Ponto de Gelo
30 °C a 500 °C
500 ºC a 1600 ºC
1600 ºC a 2500 ºC
0,01 ºC
0,005 ºC
0,01 ºC
0,01 ºC
0,1 ºC
0,2 ºC
0,5 ºC
0,5 ºC
0,1 %
0,2 %
10 % a 90 %
2%
Liquid nitrogen boiling point  77 K
(-196 ºC) (by comparison)
83,8058 K (argon triple point) to
273,16 K (water triple point)
-38,8344 ºC (mercury triple point) to
29,7646 ºC (gallium melting point)
0 ºC to 29,7646 ºC (gallium melting
point)
0 ºC a 156,5985 ºC (indium freeze
point)
0 ºC a 231,929 ºC (tin freeze point):
0 ºC a 419,527 ºC (zinc freeze point):
0 ºC a 660,323 °C (aluminium freeze
point)
0 ºC a 961,78 ºC (silver freeze point):
231,929 ºC (tin freeze point):
419,527 ºC (zinc freeze point):
660,323 ºC (aluminium freeze point)
961,78 ºC (silver freeze point)
Copper freeze point (1084,62 ºC)
5 · 10-3 ºC
2 · 10-3 ºC
1 · 10-3 ºC
1 · 10-3 ºC
3 · 10-3 ºC
3 · 10-3 ºC
5 · 10-3 ºC
1 · 10-2 ºC
5 · 10-2 ºC
0,4 ºC
0,4 ºC
0,4 ºC
0,4 ºC
0,5 ºC
Metrological Control
CONTACT
EQUIPMENT
TESTS
Measuring Instruments and
Pattern Approval
Temperature recorders used for the
control of ultra-frozen food in transport
and store houses.
LEGISLATION
Portaria n.º 1129/2009 de 1
de outubro
INSTITUTO PORTUGUÊS DA QUALIDADE (Portuguese Institute for Quality)
Rua António Gião, 2 PT-2829-513 Caparica
TEMPERATURE LABORATORY
THERMOMETRY
Head: Engª. Isabel Lóio
Tel: +351 212 948 163 E-mail: iloio@ipq.pt
ITS90
Head: Engª. Liliana Eusébio
Tel +351 212 948 156 E-mail lilianae@ipq.pt
Manuela Oliveira
Tel: +351 212 948 196
E-mail: moliveira@ipq.pt