Matters needing attention when using Japan's Fuji transmitter
Japan's Fuji transmitter is composed of a remote sealing device added to the ordinary transmitter. The remote sealing device consists of three parts: the flanged diaphragm, the capillary and the filling liquid in the capillary. When working, the measured medium acts on the isolation diaphragm of the flange diaphragm, and the pressure is transmitted to the sensitive element of the transmitter through the filling liquid in the capillary. After conversion, the instrument outputs the corresponding signal.
Japan's Fuji transmitter divides the filling liquid in the capillary into 10 types according to the different use requirements, and these 10 kinds of filling liquid have different requirements for the ambient temperature, process temperature and static pressure lower limit of the transmitter. Requirements, see the table below for details:
Ambient temperature requirements:
-20°C to 80°C, (for LCD digital display)
-40℃ to 60℃, (for built-in arrester)
-10°C to 85°C, (for "H, S, K" selection codes in silicone oil filling fluid)
+20°C to 85°C, (for "J, T" selection codes in silicone oil filling fluid,)
Process temperature and static pressure lower limit requirements:
|
Filling fluid |
Model code No. 13 |
Process temperature
|
Filling fluid density |
Static pressure lower limit |
|
Silicone oil |
H |
-15 to 250℃ |
1.07 |
atmospheric pressure |
|
J |
+85 to 300℃ |
1.09 |
|
Y |
-40 to 120℃ |
0.95 |
2.7KPa abs |
|
S |
-15 to 250℃ |
1.07 |
|
T |
+85 to 300℃ |
1.09 |
|
K |
-15 to 200℃ |
1.07 |
0.13KPa abs |
When using the transmitter whose 13th digit of the selection code is "J, T", the filling liquid is silicone oil with a specific gravity of 1.09. The silicone oil of this specification is very viscous, and the process temperature should be ensured between +85 and 300°C. The ambient temperature is guaranteed to be between +20 °C and 85 °C, so that the transmitter can work well, so the capillary tube of this specification should be heat traced and insulated. It is recommended to use hot water for heat tracing. After heat tracing and heat preservation, the temperature of the capillary is about 60-80 °C, which should not be too high. Transmitter performance deteriorates.
