© Isothermal Technology
Page 27 of 102
923 milliK manual - issue: 1.10
Reference
Junction
Junction
Cu
Cu
M+
M-
+tc
4
5
6
1
2
I-
V+
V-
3
I+
Isothermal
Environment
Channel A
Channel B
When using a thermocouple with external reference junction compensation, the ‘Reference’
parameter in the
Settings
Window should be set to the channel used to measure the
reference junction (see section 3.3.4). Also, you MUST use a copper miniature thermocouple
connector in order to avoid introducing unwanted additional thermal EMFs. Only channels
configured to measure temperature (i.e. having a Conversion defined) appear in the
‘Reference’ parameter list. Thermocouple channels do not appear in the ‘Reference’
parameter list in order to avoid circular dependencies.
For greater accuracy, you can immerse the reference junction in an ice-point at 0°C (see
section 3.3.3).
3.3.3 Using an Ice-Point for the Reference Junction
The best measurement uncertainty is generally achieved by immersing the reference junction
in an ice-point and measuring the EMF it generates (Isotech can provide ice-point reference
systems for this application):
Reference
Measurement
Junction
Junction
Ice Point
Cu
Cu
M+
M-
When using a thermocouple with the reference junction in an ice point, the ‘Reference’
parameter in the
Settings
Window should be set to 0°C (see section 3.3.4). Also, you
