Endress+Hauser silometer FMC 671 Z - Other Applications; Dry Calibration for Continuous Level Measurement with Deltapilot Probes

8 Other Applications
This chapter describes the configuration of Silometer FMC 671 Z/676 Z for other
applications. The applications described are:
• »Dry Calibration« for continuous level measurement with Deltapilot probes
• Level limit switching
• Continuous level measurement with independent level limit detection
• Level measurement with automatic calibration correction
8.1 »Dry calibration« for continuous level measurement with
Deltapilot probes
For Deltapilot probes it is possible to calibrate the Silometer FMC 671 Z/676 Z »dry« by
using the probe characteristics. For this alternative calibration you need:
• the »zero frequency« and »sensitivity« of the sensors,
• the »empty« level or offset at which the measurement should start
• the maximum height
• the density of the liquid.
The calibration is performed with an empty tank at atmospheric pressure.
Probe constantsThe probe constants are listed in table 9.3, page 55:
• The zero frequency is marked »f
o
« in Hz. This is the standard frequency of the
probe at atmospheric pressure.
- Provided the sensor is unpressurized, the actual frequency, which takes into
account orientation effects, can be read at V0H8.
• The sensitivity is marked »∆f« in Hz/mbar. This is the increase in frequency for
every mbar increase in hydrostatic pressure.
These parameters are entered at V3H5 and V3H6 respectively.
BA063E39
Max. level, e.g. 10 m,
= 980.7 mbar
Sensitivity V3H2
Pmbar at max. level
Display at max. level
Offset V3H1
P =
ρ
x g x
∆
h mbar
Max. display e.g. 1526
"Empty"
∆
h
Fig. 8.1:
Parameters required for
»dry calibration« of the
Silometer FMC 671 Z/676 Z,
.....
Silometer FMC 671 Z/676 Z Chapter 8: Other Applications
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