SOR RF Continuous Level Transmitter - Manual (Page 7)

Form 837 (05.13) ©SOR Inc. 7/16
Probe and Transmitter Performance Verifi cation
Probe Check Remove the transmitter from the probe. With no process on the probe, check
the resistance from the probe to ground. Resistance less than 1MΩ indicates leakage in the
probe. With process touching the probe, check the resistance from the probe to ground.
Resistance of 100KΩ or less in the case of a bare probe with conductive material indicates
that an insulated probe is required. In any other case, a defect in the probe is indicated.
Transmitter Drift Check If the output of the transmitter is drifting, it is important to verify
if the drift is due to the probe or the transmitter. If the probe is connected and installed
properly, it will not drift.
Remove the probe from the transmitter. Without touching the calibration settings, connect
a capacitance across the probe to ground input. See Figure 9 on page 5. Change the
capacitance until the transmitter output is 4.00 mA. Observe the zero point reading for
twenty four hours. If the reading is stable, then the probe or the application is the source
of the drift.
CE Mark Installation
When subjected to an RF interference, the 670K9
will maintain the +/-1% accuracy in all frequency
ranges with the following exception:
The unit is susceptible to a conducted RF
interference in the range of 31-40MHz, reducing
the accuracy to +/-1.3%. The +/-1% accuracy is
maintained above and below this range.
In order to achieve the stated accuracy for 670K9,
a shielded cable, cable gland, shield beads, and
the probe should be mounted in a metallic vessel.
SOR recommends using a shielded cable made
of PVC insulation around a tinned copper braid
shield (Olflex CY cable or equivalent). Refer to
illustrations for installation of shield beads.
POWER WIRE
SHIELD BEAD
Install end of bead
as close to cable
gland as possible
2 Loops
POSITIVE
NEGATIVE
Long/Slender
bead
2 Loops
1 Loop
Short/Fat bead
PROBE WIRE
SHIELD BEAD