
Three-wire RTD
Figure 8-3:
Consult the table for resistance-temperature data. Lead resistance is about 0.05 ohm/ft at 25 °C.
Therefore, 15 feet of cable increases the resistance by about 1.5 ohm. The resistance between the
RTD return and RTD sense leads should be less than 2 ohms.
RTD resistance values
Table 8-1:
Temperature
Pt-100 resistance
Pt-1000 resistance
0 °C (32 °F)
100.0 ohms
1000 ohms
10 °C (50 °F)
103.9 ohms
1039 ohms
20 °C (68 °F)
107.8 ohms
1078 ohms
25 °C (77 °F)
109.6 ohms
1096 ohms
30 °C (86 °F)
111.7 ohms
1117 ohms
40 °C (104 °F)
115.5 ohms
1155 ohms
50 °C (122 °F)
119.4 ohms
1194 ohms
60 °C (140 °F)
123.2 ohms
1232 ohms
70 °C (158 °F)
127.1 ohms
1271 ohms
80 °C (176 °F)
130.9 ohms
1309 ohms
90 °C (194 °F)
134.7 ohms
1347 ohms
100 °C (212 °F)
138.5 ohms
1385 ohms
•
If a connections is open or shorted and it should not be, the sensor has failed.
Replace the sensor.
•
If the measured resistances are acceptable, go to Step 3.
3.
Check the transmitter. Disconnect the RTD sensor leads and wire the circuit shown
in
. Set the resistance to the value for 25 °C (77 °F) shown in
measured temperature should equal 25 °C (77 °F) within ±1 °C.
Diagnostics and troubleshooting
62
Rosemount 5081
Содержание Rosemount5081
Страница 1: ...Instruction Manual LIQ MAN 5081 Rev A September 2017 Rosemount 5081 Explosion Proof Transmitter ...
Страница 4: ......
Страница 10: ...Contents vi Rosemount 5081 ...
Страница 12: ...Startup procedure 2 Rosemount 5081 ...
Страница 23: ...Mounting 5081 on a pipe Figure 3 2 Installation Instruction Manual 13 ...
Страница 24: ...Installation 14 Rosemount 5081 ...
Страница 28: ...Wiring 18 Rosemount 5081 ...
Страница 50: ...Programming basics 40 Rosemount 5081 ...
Страница 130: ...Diagnostics and troubleshooting 120 Rosemount 5081 ...
Страница 136: ...Digital communications 126 Rosemount 5081 ...
Страница 138: ...NOTICE Consult the factory for additional information regarding service or repair Return of material 128 Rosemount 5081 ...
Страница 140: ...Engineering drawings 130 Rosemount 5081 ...
Страница 141: ...Engineering drawings Instruction Manual 131 ...
Страница 142: ...Engineering drawings 132 Rosemount 5081 ...
Страница 143: ...Engineering drawings Instruction Manual 133 ...
Страница 144: ...Engineering drawings 134 Rosemount 5081 ...
Страница 145: ...Engineering drawings Instruction Manual 135 ...
Страница 146: ...Engineering drawings 136 Rosemount 5081 ...
Страница 151: ...EU Declarations of Conformity 138 Rosemount 5081 ...