ST2515 Operation Manual
21
ta is the environment temperature.
R1 is the resistance at the start of contact.
R2 is the resistance after the display is stable.
K is the variance ration of the environment temperature coefficient when the conductor is at
0°C.
For example
When R1 is 100mΩ, t1 is 20°C, R2 is 105mΩ, ta is 25°C and k is 235.
Δ
t
(k + t1)
–
(k + ta)=
(235 + 20)
–
(235+25)=7.75°C
The temperature after the resistance is stable is calculated as the following formula:
t
R
= ta +Δt = 25 +7.75 = 32.75°C
Where, k =
-
t0, if α
t0
= 3930ppm, k is 234.5 (where if α
t0
is 3930ppm, t0 is 20°C)
Analog Input
Touch the T.SENS soft key to select the temperature input type. AnLG_In is analog input and the
corresponding forma is:
1
2
1
2
2
1
)
(
*
1
2
1
2
V
V
V
T
V
T
ge
InputVolta
V
V
T
T
-----------------------------------------------------------------------------------------------------------------------------
NOTE: V1 and V2 range from 00.00V to 02.00V while T1 and T2 range from -99.9°C to 999.9°C.
Metallic material
Metal
[%]
Material
density
(x10
3
)
[kg/m
3
]
Conductivity
Temperature
coefficient
(20°C)
[ppm]
Annealed copper
Copper>99.9
8.89
1.00 to 1.02
3810 to 3970
Hard-drawn copper
Copper>99.9
8.89
0.96 to 0.98
3370 to 3850
Cadmium copper
Cadmium: 0.7 to
1.2
8.94
0.85 to 0.88
3340 to 3460
Silver copper
Silver: 0.03 to 0.1
8.89
0.96 to 0.98
3930
Chromium copper
Chromium: 0.4 to
0.8
8.89
0.40 to 0.50
0.80 to 0.85
20
30
