Acid and alkali level gauging
The tanks containing corrosive substances, for example, acid, are characterized by high corrosive influence on the details contacting directly with the product and air film above it. That’s why all the contact instruments of acid level gauging and the classical radar level gauges used to measure the acid level have the sensitive element made of special materials which results in the higher cost of the instruments, however, doesn’t protect from the corrosion or the breakdown of the level sensor.
For example, the sensitive element (wire or pivot) of the contact level gauges has the fluoroplastic coating layer which can be damaged in the process of shipment or installation of the level gauge. As for the noncontact radar level gauges, they have the pivot fluoroplastic antenna, but this antenna reduces the level gauge sensitivity as it expands the divergence angle of the gauging "beam". Besides, “dew” often appears on the pivot antenna of the level gauge, if it contacts with the atmosphere saturated with acid vapours, therefore, it also contributes to the lower sensitivity of the level gauge, the lower stability of level gauging and the higher measurement inaccuracy.
The use of noncontact ultrasonic level gauges for acid level gauging is also accompanied by some difficulties. In the process of storing the acid in the tank, the great amount of vapour congregates above the product surface. These vapours are distributed inequaly throughout the tank height. The ultrasonic level gauge measures the sound-wave propagation delay time to determine the product level, and the sound wave velocity depends very much on the environment in which this wave propagates, in our case, on the composition of the atmosphere above the acid. That’s why while the sound wave is propagating from the level sensor to the acid and is returning back to the level sensor, its velocity changes many times in the unpredictable way, which results either in the dramatic increase in the inaccuracy of level gauging (if the exact value of velocity is unknown, it's impossible to find the distance travelled per unit of time), or in failure to measure the product level (loss of level).
Application features
ULM level gauges, unlike the most level gauges of other brands, don’t require the level sensor antenna to be in direct contact with the tank interior content, as the antenna isn't plunged into the tank. AS for ULM-31A2 level gauge, it’s designed to handle the problems of gauging the product level in the tanks with the corrosive environment and suits ideally to solving these tasks.
The level sensor is fixed outside the tank (on its roof) and can measure the product level accurately without being in contact with the substance. The body of ULM4-5 level sensor is entirely made of non-metallic acid-resistant material. The level sensor antenna is entirely located in the gauge body and is protected from the product corrosive evaporation.
Methods of ULM level gauges installation on the tank containing the acid
ULM-11 level gauges ULM-31A2 level gauge
ULM-11A1 level gauge
ULM-11A1 level gauge
Thus, the contact between the internal corrosive environment and the elements of the level sensor and its antenna (sensitive element) is absolutely ruled out. ULM level gauges measure the level of different acids such as:
- sulphuric acid;
- chlorhydric acid;
- orthophosphoric acid;
- nitric acid;
- fluohydric acid, etc.
The level gauging system of the tank farm can include several different ULM radar level gauges which are integrated in a unified system. All the ULM radar level gauges have fully compatible system of commands and unified embodiment which allows, on the basis of ULM level gauges, to create the most efficient technology in price-quality terms.
