Because of process requirements, scale measurements are very popular in automation systems.
Most often measured are storage containers and containers, in that blends of raw materials in definite proportions are created.
The main measuring elements are scale sensors, that are placed under backstays of containers or platforms. In connection with appropriate scale sensors, the measurements of the weight , proportioning of raw materials or creating of the appropriate recipes with automatic proportioning, stirrer service and container clearing can be realized.
The rules of the operation
Strength, pressure or weight can be resolved into measurement of the strain. The sensor, that change the size of strain in the measuring element (for example like a beam or a diaphragm) into electric signal is most often a strain bridge.
A tensometer is a segment of the electric conductor, set in the shape of, so called, measuring ladder. The reactance depends on three elements: length, cross-section area and a material sort.
The strengths, that influence on the mechanical elements cause, that strains are created inside of it, and this fact is a reason of changing the measuring elememts resistance in the side-lines of the strain bridge and getting a electric signal at the outway of the bridge.
The dependence of the mechanical changes is specified by rights of phisics. The way of hooking up the strain bridgrs depends on their introduction.
Scale measurements let realize the measurements of materials that are situated in the containers, without a dependence on the temperature, pressure or changes of the density of the medium inside of it.
A measuremetn of the weight of the products in the containers (depending on the place of the container in the process) influes on the choice of the sensors. It's connected with measuring scope and required measuring accuracy. Store containers are large capacities that doesn't require very accurate measurements. Process containers requires high accuracy while less measuring scopes.
A typical location of the sensors under the container is to place 3 sensors on the circle in every 120. It asures a stability of the construction, secures the container of the location changes, and causes, that the measurements are independent on the spreading of the materials inside of it.
The sensors of the strength can be used to measure the strenght of the sheet metal tensioning, strain of the fabric or paper coil in the process of continous production, checkin the endurance of the materials.
The sensors are made of acid-resistant or galvanized steel in the scope of capacity from 100kg to 50 t. Compact structure and mechanical resistance causes a long-lasting work without any breakdowns.