Curve Breakpoints - Omega CYD211 User Manual

3.13.2

Curve Breakpoints

Temperature response data of a calibrated sensor must be reduced to a table
of breakpoints before entering it into the instrument. Each breakpoint
consists of one value in sensor units and one temperature value in Kelvin.
Linear interpolation is used by the instrument to calculate temperature
between breakpoints. From 2 to 200 breakpoints can be entered as a curve.
The instrument will show an error message on the display if the sensor input
is outside the range of the breakpoints. No special endpoints are required.
Sensor units are defined by the format setting in Table 3-7.
Breakpoint setting resolution is six digits in temperature. Most temperature
values are entered with 0.001 resolution. Temperature values of 1000 K and
greater can be entered to 0.01 resolution. Temperature values below 10 K
can be entered with 0.0001 resolution. Temperature range for curve entry is
1500 K.
Setting resolution is also 6 digits in sensor units. The curve format
parameter defines the range and resolution in sensor units as shown in
Table 3-7. The sensor type determines the practical setting resolution.
Table 3-7 lists recommended sensor units resolutions. For most sensors,
additional resolution is ignored.
The breakpoints should be entered with the sensor units value increasing as
point number increases. There should not be any breakpoint locations left
blank in the middle of a curve. The search routine in the Model CYD211
interprets a blank breakpoint as the end of the curve.
Table 3-7. Recommended Curve Parameters
Type
Silicon Diode
GaAlAs Diode
Platinum 100
Platinum 1000
Rhodium-Iron
Carbon-Glass CGR-1-1000
Cernox
Germanium GR-200A-100
Rox
3-12
Omega Model CYD211 User's Manual
Typical Lake
Unit
Shore Model
DT-470 V
TG-120 V
PT-100
Ω
PT-100
Ω
RF-100
Ω
Ω
CX-1030
Ω
Ω
RX-102A
Ω
Limit
Format Coefficient
(K)
V/K 475 Negative
V/K 325 Negative
/K 800 Positive
Ω
/K 800 Positive
Ω
/K 325 Positive
Ω
log /K 325 Negative
Ω
log /K 325 Negative
Ω
log /K 325 Negative
Ω
log /K 40 Negative
Ω
Recommended
Sensor Resolution
0.00001 (V)
0.00001 (V)
0.001 ( )
Ω
0.01 ( )
Ω
0.001 ( )
Ω
0.00001 (log )
Ω
0.00001 (log )
Ω
0.00001 (log )
Ω
0.00001 (log )
Ω
Operation