KROHNE OPTIMASS Series Handbook page 97

Zero Problems
•
Perform auto zero, observe the displayed value, it should be stable and lower than +/- 0.5%
•
If the result is bad:
Stop flow, set 3.1.1 Low flow cut off to 0, 3.1.3 Flow Mode to "+/-", perform auto zero,
and totalise over 2 minutes. Compare totalised flow to specified zero stability.
For best process results, zero setting should be performed on process fluid at process temperature.
High Zero's can be caused by: Leaking valves, Air/Gas inclusions, Coating on tube.
Driver or Sensor Coil Fault
Typical inductance and resistance values:
OPTIMASS 7000
OPTIMASS Inductance (mH)
7000
Driver
06/10 5.30 (4.32)
15 11.7
25/40 13.1 (11.3)
50/80 23.5 (12.9)
•
The above data are provided as a rough guide only.
•
Damaged magnet coil assembly: Inductance values in brackets.
•
Driver = Black and Grey.
•
Sensor A = White and Yellow. Sensor B = Green and Purple.
•
RTD = Red and Blue (530...550 Ω) at ambient temperature
•
Tube strain = Red and Brown:
•
IC strain = Brown and Orange
•
Resistance values outside these values could indicate a circuit failuire. Meter may be in start-up or
have measuring errors.
•
All circuit should be isolated from ground (meter case) and each other: >20MΩ. If circuits are shorting
to ground, meter may be in start-up.
Caution:
Fluid may be in secondary containment – possible tube failure. Depressurise and safely remove from line
as soon as possible.
OPTIMASS 3000 (7100)
OPTIMASS Inductance (mH)
3000 (7100)
Driver
01 1.2 (1.2)
03/04 2.6 (8.9)
•
The above data are provided as a rough guide only.
•
Damaged magnet coil assembly: Inductance values in brackets.
•
Driver = Purple/Black and Orange/Grey.
•
Sensor A = White and Yellow. Sensor B = Green and Yellow.
•
RTD = Red and Blue (530...550 Ω) at ambient temperature
•
Resistance values outside these values could indicate a circuit failure. Meter may be in start-up or have
measuring errors.
•
All circuit should be isolated from ground (meter case) and each other: >20MΩ. If circuits are shorting
to ground, meter may be in start-up.
Caution:
Fluid may be in secondary containment – possible tube failure. Depressurise and safely remove from line
as soon as possible.
Sensor A/B
17.32 (10.36)
(8.9) 17.32 (10.36)
17.32 (10.36)
17.32 (10.36)
OPTIMASS 7000 – 06
OPTIMASS 7000 – 10...80
OPTIMASS 7000 – 06...10
OPTIMASS 7000 – 15...80
Sensor A/B
7.2 (7.2)*
10.5 (10.36)
Installation and Operating Instructions OPTIMASS
Resistance (Ohm)
Driver
37 - 42
47 - 51
40 - 41
49 - 51
600 - 800Ω at ambient
420 - 560Ω at ambient
225 - 275 Ω at ambient
Not fitted
Resistance (Ohm)
Driver Sensor A/B
54 – 60 105 - 110
43 – 50 132 - 138
Sensor A/B
147 - 152
147 - 152
147 - 152
147 - 152
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