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Measuring Accuracy Up to +/- 0.008 (0.2 mm) |
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Resolution Better Than 0.004 (0.1 mm) |
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Temperature Compensated |
This high-precision and robust level sensor is designed to provide continuous gauging of liquid media levels in tanks. The measuring principle used by the sensor exploits the physical effect of magnetostriction and is largely unaffected by temperature. Magnetostriction is particularly ideal where level measurements are required to be extremely accurate, e.g. in the chemical industry. The level sensor outputs measuring signals in the range of 4 to 20 mA. Available in lengths of 7.87" to 157.48" (200 to 6,000 mm), it is compatible with a variety of tank dimensions. It also comes in the following versions:
The explosion-proof version of the level sensor can be installed in potentially explosive atmospheres in which electrical equipment of category 1 (zone 0) or category 1/2 (zone 0/1) are required. Operating on the digital HART protocol, the HART level sensor is able to output the position of the first, second or both floats.
Inside the probe tube there is a rigid wire made of magnetostrictive material.
The sensor circuitry emits pulses of current through the wire, generating a
circular magnetic field. The level transmitter is a magnet, which is integrated
into the float. Its magnetic field magnetizes the wire axially. Since the two
magnetic fields are superimposed, around the float magnet a torsion wave is
generated which runs in both directions along the wire. One wave runs directly
to the probe head while the other is reflected at the bottom of the probe tube.
The time is measured between emission of the current pulse and arrival of the
wave at the probe head. The position of the float is determined on the basis of
the transit times.