Technical information

Ultrasonic Level Sensor LUC-M**
Performance characteristics
DOCT-0805F 01/2010 185414
10
Performance characteristics
Reaction time The reaction time depends on the parameter settings. The minimum values are:
• 2-wire devices (LUC-M10, LUC-M20, LUC-M40): min. 2 s
• 2-wire devices (LUC-M30 – PROFIBUS PA): min. 2 s
• 4-wire devices (LUC-M10, LUC-M20, LUC-M30, LUC-M40): min. 0.5 s
Reference operating
conditions
• temperature = +20 °C (293 K)
• pressure = 1013 mbar abs.
•humidity = 50 %
• ideal reflective surface (e. g. calm, smooth fluid surface)
• no interference reflections within signal beam
• set application parameters:
– tank shape = flat ceiling
– medium property = liquid
– process conditions = calm surface
Measured value resolution
Pulse frequency • 2-wire devices (LUC-M10, LUC-M20, LUC-M40): max. 0.5 Hz
• 2-wire devices (LUC-M30 – PROFIBUS PA): max. 0.5 Hz
• 4-wire devices (LUC-M10, LUC-M20, LUC-M30, LUC-M40): max. 2 Hz
The exact values are dependent on the type of device and the parameter settings.
Measuring error Typical specifications for reference operating conditions (include linearity, repeatability, and
hysteresis):
1)
whichever is greater
Influence of the vapour
pressure
The vapor pressure at 20 °C (293 K) gives a hint on the accuracy of the ultrasonic level
measurement. If the vapor pressure at 20 °C (293 K) is below 50 mbar, ultrasonic level
measurement is possible with a very high accuracy. This is valid for water, aqueous solutions,
water-solid-solutions, dilute acids (hydrochloric acid, sulfuric acid, ...), dilute bases
(caustic soda, ...), oils, greases, slurries, pastes, ...
High vapor pressures or outgassing media (ethanol, acetone, ammonia, ...) can influence the
accuracy. If conditions like these are present, please contact the Pepperl+Fuchs support.
Sensor Measured value resolution
LUC-M10 1 mm (0.04 in)
LUC-M20 1 mm (0.04 in)
LUC-M30 2 mm (0.08 in)
LUC-M40 2 mm (0.08 in)
Sensor Measuring error
LUC-M10 ± 2 mm (0.08 in) or 0.2% of set measuring range (empty calibration)
1)
LUC-M20 ± 2 mm (0.08 in) or 0.2% of set measuring range (empty calibration)
1)
LUC-M30 ± 4 mm (0.16 in) or 0.2% of set measuring range (empty calibration)
1)
LUC-M40 ± 4 mm (0.16 in) or 0.2% of set measuring range (empty calibration)
1)