© Isothermal Technology
Page 18 of 102
923 milliK manual - issue: 1.10
3 Detailed Description by Function
This section describes all the features available on the milliK by function. If you wish to learn
how to do something with your milliK use the table of contents on page 2 onwards to look up
the appropriate section.
3.1 Using a PRT/SPRT with milliK
The milliK can measure the resistance of PRTs and SPRTs. It can convert measurements
from resistance to temperature units (K, °C or °F) so that you can make precise temperature
measurements or calibrate other thermometers from a reference standard.
The milliK provides two resistance measurement ranges which are optimised for PRTs and
SPRTs:
•
0-115
Ω
: optimised for 25.5
Ω
SPRTs
•
0-460
Ω
: optimised for 100
Ω
PRTS
The milliK will measure 25.5
Ω
SPRTs on the 460
Ω
range, but better measurement
uncertainty is achieved by using the 115
Ω
range. The sense current for both ranges is 1mA
(or 1.428mA).
Connect your PRTs/SPRTs to either of the Lemo 6-pin circular connectors on the front panel
(see section 4.1 for pin-out and connection details). Ensure that the miniature thermocouple
connector for the same channel is unused (since it is connected in parallel with the Lemo
connector). Isotech can (optionally) supply thermometers fitted with a suitable Lemo
connector. Your milliK is supplied with two Lemo connectors for you to use with your own
PRT/SPRT (or thermistor). The part number for this connector is:
Lemo part number: FGG.1B.306.CLAD62Z
Additional connectors are readily available internationally from Farnell Electronics and can
be ordered via their website
www.farnell.com
(Farnell stock code 3817325).
Channels 1 and 2 are not isolated from each other, but are isolated from Channel 3 and from
the digital interfaces in order to optimise immunity to external noise sources.
