Balluff BFT Serie Manual De Instrucciones página 15

Temperature transmitter
BFT _ _ _ _-_ _002-_ _ _A1A-_ _
Operation
Probe break and short circuit
Probe break and short circuit are indicated after definitive
recognition (after approx. 1 s). If this error is caused by a
malfunction, a relevant measuring signal must also be
present for approx. 1 second to return to measuring mode.
From the time of detection until the error is signaled the
last relevant measurement value is output on the current
loop.
This allows a "true" cable break or short circuit to be
continuously indicated. In case of a "false" probe break or
short circuit the transmitter can return to measuring mode.
Media temperature outside the span
The media temperature configured in the transmitter is
exceeded the transmitter will continue to run linear within
the following limits:
3.8 mA measuring range start (MBA); 20.5 mA measuring
range end (MBE). If these are exceeded an error is
indicated
Current values for error indication
downscale ≤ 3.6 mA
upscale ≥ 21.0 mA
Hysteresis when returning to the measuring span
After the linear error limits are exceeded a hysteresis of 0.1
mA must be exceeded when returning to the measuring
span. This hysteresis prevents the transmitter from jumping
back and forth between error indication and measuring
mode at the edge of the error limits.
3,8 mA 4 mA
3.8
Error
4...20 mA
...
indication
4 mA
Measuring mode
Error
indication
3,9 mA
Fig. 7: Error limits and permissible measuring range
www.balluff.com
20 mA 20,5 mA
20
Error
...
indication
20.5 mA
Error
indication
20,4 mA
Disassembly
WARNING
Health hazard!
Measuring materials which are irritating, toxic,
carcinogenic, radioactive etc. represent a health hazard.
► Remove all remnants of measuring materials from
the temperature transmitter before returning or
disposing of it.
CAUTION
Combustion hazard!
When disassembling there is a risk from escaping
hazardous hot measuring materials.
► Before removing the temperature transmitter allow it
to cool sufficiently!
► Temperature transmitter must be uninstalled only
when not under pressure!
Disposal
Medium remnants on the device may result in a hazard to
the operator and the environment. Take appropriate
precautionary measures and dispose of the device
properly.
Observe the national regulations for disposal.
english 5