SBC PCD1 Series Manual page 200

Saia-Burgess Controls AG
Temperature measurement with Pt 1000
In the temperature range – 50 °C to + 200 °C, the following formulae can be used for
working to an accuracy of ± 1 % (± 1.5 °C). Repeating accuracy is significantly higher.
T[° C]=
2.08 - (0.509 • 10 - ³ • DV)
T=temperature in ° C
Example 1: digital value DV=562
T[° C]=
2.08 - (0.509 • 10 - ³ • 562)
2.08 • (261.8 + T)
DV=
1 + (0.509 • 10 - ³ • (261.8 + T))
DV=digital value (0 ... 1 023)
Example 2: preset temperature T = –10 °C
2.08 • (261.8 - 10)
DV=
1 + (0.509 • 10 - ³ • (261.8 - 10))
Resistance measurement up to 2.5 kΩ
Special temperature sensors or any other resistances up to 2.5 kΩ can be connected
to the PCD2.W220. The digital value can be calculated as follows:
4092 • R
DV=
(7500 + R)
where 0 ≤ DV ≤ 1023 and R=the resistance to be measured in Ω.
Manual Manual PCD 1 / PCD 2 Series │ D ocument 26 / 737 EN22 │ 2 013-11-26
DV
- 261,8
temperature T in ° C ?
562
- 261,8
corresponding digital value DV ?
DV=digital value (0 ... 1 023)
= 51.5 °C
T=temperature in ° C
= 464
Input/output (I/O) modules
Analogue input modules
5
5-64