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9.4 DIFFERENTIAL PRESSURE TRANSMITTER – FUJI
Do not open the cover from the amplifier with active DC power supply in hazardous
area.
9.4.1 Zero adjustment of DPT – FUJI
1. Keep the transmitter energised for at least 10 minutes.
2. Remove the covers from the DPT electronics housing.
3. Connect an ammeter to the “CHECK” terminals (+ and -) of the transmitter as shown is
drawing 0810-2010.
4. Check that the “Zero/Span adjustment selector switch” is switched to “ZERO”.
Refer to the illustrations in drawing 0899-1249.
5. Apply the lower pressure value.
6. Wait for the pressure to stabilise.
7. Slide away the “ZERO” cover on the DPT electronics housing and adjust the zero point by
turning the adjustment screw as shown in drawing 0899-1249.
The lower pressure value should then correspond with an output of 4mA.
8. Remove the ammeter and close the covers. Ensure that the sealing ring is installed
otherwise the transmitter is not in accordance with IP67.
NOTE:
After adjustment, the transmitter should be kept energized for about 10 seconds to write
the adjustment results into the memory.
9.4.2 Span adjustment of DPT – FUJI
1. Keep the transmitter energised for at least 10 minutes.
2. Remove the covers from the DPT electronics housing and read the calibration data plate
affixed to the inside of the cover.
3. Connect a suitable pressure gauge and air supply to “+” side of the DPT. Make sure that “-”
side vents to atmosphere.
4. Connect an ammeter to the “CHECK” terminals (+ and -) of the transmitter as shown is
drawing 0810-2010.
5. Check that the “Zero/Span adjustment selector switch” is switched to “SPAN”
Refer to the illustrations in drawing 0899-1249.
6. Apply pressure shown as “upper calibration value” on calibration data plate of the DPT.
7. Wait for the pressure to stabilise.
8. Slide away the “ZERO” cover on the DPT electronics housing and adjust the output current
to 20mA by turning the Zero/Span screw as shown in drawing 0899-1249.
9. Set the pressure back to the lower pressure value and check that the output is 4mA.
10. After adjusting the span as mentioned above, set the selector switch back to “Zero” before
using the transmitter.
11. Remove air tools and ammeter and close the covers. Ensure that the sealing ring is installed
otherwise the transmitter is not in accordance with IP67.
NOTE:
After adjustment, the transmitter should be kept energized for about 10 seconds to write
the adjustment results into the memory.
WARNING:
IN HAZARDOUS ZONES WITH EXPLOSION PROOF REQUIREMENTS THE COVER
MUST BE TIGHTENED AT LEAST 7 TURNS.
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