The 670 Family consists of quartz sheath (recommended) and metal sheath models with Ro of 25.5 ?.
The 670SQ is our latest thermometer, to be specifically designed to give optimum performance up to the Aluminium point. Its construction permits the four internal platinum lead wires to expand and contract in the same manner as those of silver-point thermometers. The all-quartz construction of the sheath gives the most stable performance with minimal drift, and a unique platinum radiation shield prevents heat radiating up the inside of the sheath.
The 670SQ can be supplied with RTPW and Wga only or with full UKAS calibration. “With calibration” means that you will get an ITS-90 accepted Fixed Point calibration. For best accuracy, the recommended maximum measuring current for the 670SQ is 1 mA.
The 670SQ 650 mm long is our recommended SPRT offering ultra stability, vibration, shock, immersion (recommended sufficient immersion: 270 mm) and self heating characteristics.
General
specifications
Measuring range
|
-200°C to 670°C
|
Nominal resistance
|
25.5 ? or 100 ?
|
Resistance ratio
|
Wga > 1.11807 as required by ITS-90
|
Sensitivity
|
0.1 ? /°C (25.5 ?)
0.4 ? /°C (100 ?)
|
Long term drift
|
From 0.001°C / year depending on use
|
Models 25.5
?
Reference
|
Temperature range
|
Sheath
|
Diameter
|
Length
|
Sensing length
|
Standard
|
Notes
|
670SQ/25/480
|
-200 to 670°C
|
Quartz
|
7.5 mm
|
480 mm
|
35 mm
|
ITS-90
|
Recommended for wide range use in the
Primary laboratory
|
670SQ/25/650
|
-200 to 670°C
|
Quartz
|
7.5 mm
|
650 mm
|
35 mm
|
ITS-90
|
670SL/25/480
|
-200 to 165°C
|
Metal
|
6 mm
|
480 mm
|
35 mm
|
ITS-90
|
Metal sheathed low temperature model
|
670/SH/25/480
|
-80 to 670°C
|
Metal
|
6 mm
|
480 mm
|
35 mm
|
ITS-90
|
Metal sheathed high temperature model
|
670/SH/25/650
|
-80 to 670°C
|
Metal
|
6 mm
|
650 mm
|
35 mm
|
ITS-90
|
Typical
uncertainties of 670 SPRTs with UKAS calibration
Fixed point
|
°C
|
Gamme 1
|
Gamme 2
|
Gamme 3
|
Gamme 4
|
Gamme 5
|
Gamme 6
|
TP Argon
|
-189.3442
|
0,5 mK
|
|
0,5 mK
|
0,5 mK
|
0,5 mK
|
0,5 mK
|
TP Mercury
|
-38.8344
|
0,3 mK
|
0,3 mK
|
0,3 mK
|
0,3 mK
|
0,3 mK
|
0,3 mK
|
TP Water
|
0.01
|
0,1 mK
|
0,1 mK
|
0,1 mK
|
0,1 mK
|
0,1 mK
|
0,1 mK
|
MP Gallium
|
29.7646
|
|
0,2 mK
|
|
|
|
|
FP Indium
|
156.5985
|
|
|
1 mK
|
1 mK
|
|
|
FP Tin
|
231.928
|
|
|
|
1 mK
|
1 mK
|
1 mK
|
FP Zinc
|
419.527
|
|
|
|
|
1.2 mK
|
1.2 mK
|
FP Aluminium
|
660.323
|
|
|
|
|
|
2 mK
|
