3.2Shortening of Probe
The MT2000 single probe can be cut to length prior to installation. The MT2000 default factory configuration pro- vides a measurement in engineering units with a zero referenced to the bottom of the sensing probe. The top of the probe yields a measurement equal to the probe length (Figure 3.2).
20 mAdc | Probe Length |
URV = Probe Length
LRV = 0 in. / 0 mm
4 mAdc | 0 in. / 0mm |
Factory Default Configuration
1.The default factory setup is with the instrument meas- uring “level”; This means that the display will indicate a number equal to the sensor length when the level is at the top of the vessel. When the vessel is empty it will indicate zero.
2.If readout in “level measurement units” is not desir- able, engineering units can be set to percentage (%). This will provide the readout in percentage of total level, referenced to the 4 mA and 20 mA points (LRV and URV).
3.If percentage (%) tank level readout is not desirable, proceed to Sensor Trim Section (Appendix A).
Figure 3.2
If the probe is shortened, the unit will indicate the distance as if the level was at the place where the probe was cut off as the lowest value, and read the change in EUN correctly FROM THAT POINT— to the URV.
Example: MT2000 was shipped (and trimmed) with a 10ft. probe. The probe was shortened by removing 3ft. leav- ing the total length at 7.0 ft. If the transmitter was installed with no further correction, the transmitter display (LL1) will indicate 3.0 ft. with the level at the end of the probe and 10ft. with the level at the top (a change of 7ft.). To set the transmitter to transmit 4 – 20 mA over the length of the probe, the following settings would need to be entered in the CAL menu:
LRV = 3.0 ft and URV = 10.0 ft.
If this is not desirable, one of the following can be done:
1.Change EUN = %. The level will now be shown (LL1) as 0.0% to 100.0%. (Note: LRV = 3.0 ft.; URV = 10.0 ft. in this example.)
2.Enter L1O =
3.
3.3MT2000 Guided Wave Radar Guidelines
These guidelines are not absolute limits but rather limits that will ensure optimum performance and ease of configu- ration:
Cable sensor probe is preferred over rigid rod.
Cables in tube or Pipe:
•Use P11 (3/16” DIA) cable.
•In 3” Pipe: 10 Ft. Max cable without spacers, longer cable with spacer every 10 ft.
•In 1.5” or 2” pipe: 7 ft. max cable without spacers, longer cable with spacer every 5 ft.
•Three spacer sizes available for 1.5”, 2”, or 3” sch 160 pipe.
•Two spacer materials available, Teflon and ceramic (above 400°F).
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