5.2.1.1
R(
Ω
) Conversion
EDIT SPRT 01
PROBE SER#: 1
CONVERSION: R(
Ω
)
The R(
Ω
) conversion displays the measurement as resistance in ohms rather
than temperature.
5.2.1.2
ITS-90 Conversion
EDIT SPRT 01
PROBE SER#: 1
CONVERSION: ITS-90
LO RG: 4, 83k - 273k
HI RG: 7, 273k - 933k
RTPW: 25.546738
A[4]: -1.5763669E-4
$
The ITS-90 conversion converts resistance to temperature according to the
ITS-90 specifications for SPRTs. Most PRTs and SPRTs are characterized ac-
cording to the International Temperature Scale of 1990 (ITS-90). For details
about the ITS-90 see NIST Technical Note 1265,
Guidelines for Realizing the
International Temperature Scale of 1990
. The user-defined parameters for the
ITS-90 conversion include two subranges (LO RG and HI RG), the triple point
of water resistance (RTPW), and various coefficients of the ITS-90 deviation
functions that are applicable for the selected subranges. If you select ITS-90 for
CONVERSION, you must then select one or two sub-ranges then enter the co-
efficients for the sub-ranges. You may select both a low temperature sub-range
and a high temperature sub-range. At temperatures where the high and low
ranges overlap, the low range takes precedence. If the probe is calibrated for
only one range, set the unused high or low range to NONE. If both sub-ranges
are set to NONE the temperature will be calculated using the ITS-90 reference
function. When using range 6 (273.15 to 1234.93K), note that you do not need
to enter the value for W(933.473K). This value is calculated automatically
based on the coefficients
a
6
,
b
6
, and
c
6
.
1560 Thermometer Readout
User’s Guide
36
