Level

There is currently a large selection of different methods for measuring level. Autek can supply level measuring instruments to both the land-based and offshore industry. There are a number of different media that influence the choice of the right level measuring equipment. It must be taken into account, among other things;

foam
Dust
High temperature
High pressure
Disturbing physical elements (obstructions, pumping etc.)
Change of specific gravity
Dry and moist media, ie varying relative humidity
Changing the dielectric constant (reflectivity)
Change of specific conductivity in liquids
Autek can help the customer with the right choice to achieve a successful measurement

Suppliers

level gauges

The level in the tank is indicated by a magnetic coupling from the float in the measuring tube to the outside mounted indicator. This provides an easily readable indicator that is not media affected and therefore not exposed to aging. Tanks with hazardous liquids, high pressures etc are given a safe indication where the process is isolated from the indicator. It is possible to mount both alarm contacts and transmitter for level transmitter 4… 20 mA on the outside of the pipe.

ultrasound

Ultrasonic level meters use a sound pulse that is reflected from the surface of a medium by changing the specific gravity between the air and the medium. The time the dealer uses to send and receive a reflective

level transmitters

The most widely used method for level measurement is with differential pressure based transmitters. AUTEK supplies both submersible and bottom mounted transmitters. Common to these is that they are based on measuring the difference between the static pressure inside the bottom of the container and the current air pressure for open tanks. From the submerged level transmitter, a reference tube for pressure inside the electric cable is then drawn. At closed and non-ventilated tanks, the difference between the pressure in the bottom and the top of the tank is measured.

Temperature sensor built into the pressure sensor can be supplied. Temperature compensation can then be utilized for more accurate volume calculations.

Radar Level Measurement

Radar level measurement is based on a radar signal being transmitted via an antenna, then reflected in a surface of the medium and returned to the meter with a time delay. The distance to the reflection of the surface of the medium is determined by the transit time of the micro wave signal. The level is then calculated from the tank height and the distance to the medium. Radar is widely used for measuring interface layers. One uses a led radar. This will then both measure the interface layer and the level in the tank. For this type of measurement to be successful, several conditions must be present;

The media should be constant and have clear separation layers.
The emulsion layer must be less than 5 cm.
The dielectric constant of the upper liquid must be constant and less than 10.
The dielectric constant of the lower liquid must be more than 10.
The upper layer of liquid must be larger than 15 cm, but not too large, as this will lead to excessive signal attenuation.