How to choose the pull pressure sensor
Pull pressure sensor constituted by a load cell, because of its flexible assembly, cheap, in the chemical industry has its unique application.
First, pull the pressure sensor and its characteristics
1. Pull pressure sensor Introduction
Pull pressure sensor is a practicality structural parts for the sensor. The roof, the substrate, weighing sensors, load bearing columns and supporting bolt composition.
Depending on the load bearing columns and roof, divided into fixed, semi-floating and floating three structures. In a weighing system, the use of a fixed module, a semi-floating modules make up the rest by floating modules, is generally divided into three and four of a set. Three of a three-point support, four set for four o'clock support. Pull pressure sensor can be easily mounted on the container of various shapes, suitable for the transformation of existing equipment, whether it is a container, hopper or reactors, plus pull pressure sensor can be turned into the weighing system.
2. Pull the pressure sensor characteristics
Compared with the existing electronic weighing, pull the pressure sensor biggest feature is subject to site constraints, flexible assembly, easy maintenance and inexpensive.
Scales due to the scale platform, to a certain area, and pull the pressure sensor mounted on the bearing point of the container, without additional covering. Is particularly suitable for a plurality of containers installed in parallel and the narrow field applications. Range and electronic weighing scale value of a certain size, and pull the pressure sensor consists of weighing systems, scale and dividing the value of the instrument can be permitted within the scope of their own settings as needed. Pull pressure sensor easy maintenance, if the sensor is damaged, you can adjust the scale body supporting screw top, without having to dismantle pull pressure sensor, you can replace the sensor. In addition, due to the simple pull pressure sensor structure, and thus by pulling pressure sensors weighing system, the investment is relatively small.
Second, pull the pressure sensor in the chemical industry
A large number of chemical companies use a variety of storage tanks and metering tank in material storage and production processes. But generally encountered two problems, one is material measurement issues, the second is to control the problem of the production process. According to our practice, the application of electronic pull the pressure sensor can be solved.
1. Pull the pressure sensor is applied to the measurement of material
In general, the current metering tank of liquid, mostly using the scale or flowmeter to measure. But both volume measurement, and then depending on the density of the liquid in terms of weight. Because the density and temperature and other factors, the error is relatively large, although there are mass flowmeter, but expensive, general business rarely used, and therefore electronic pull pressure sensor, a direct weighing of the material is more economical and practical.
2. Pull pressure sensor for level indication and control
Level is an important control parameter chemical production processes. In addition to the field level indication is generally level indicating instrument, in general, the use of the transmitter converts the signal into a standard electrical signal level or remote air signal to the control room. However, this method, in addition to previously mentioned level due to changes in density caused by the error, there may be due to the crystalline materials, block, etc. cause false level, and may even lead to serious accidents. In addition, due to the measurement part of the transmitter in direct contact with the measured medium, for some corrosive media, the need to use expensive corrosion-resistant materials. And pull the pressure sensor is not in direct contact with the measured medium, the above disadvantages do not exist. And weighing indicator you can use with analog output interface, received a logger, adjusting, to achieve automatic recording and control.
3. Pull the pressure sensor is applied to the feeding amount, there are strict requirements of the occasion
There are some on the feeding amount of the production process has strict requirements, many companies regard the metering tank placed directly on the floor scale up control feeding amount. But ground scale overhaul or test, you need to use lifting equipment to the metering tank hanging down too much trouble. If you use electronic pull pressure sensor for measuring the tank itself as the scale body, so there is no problem lifting, maintenance more convenient.
Third, pull the pressure sensor purchase, installation, commissioning Notes
1, the purchase considerations
Pull pressure sensor purchase, generally based on the points of support vessels to choose three or four of a set of modules range, due to the presence of the scale body (container) weight and vibration shocks, partial load and other factors, according to the following general selection rules. Multi-sensor static weighing systems:
Fixed load (scale units, containers, etc.) + change in load (demand weighed load) ≤ selection of sensors with a rated load × the number of sensors × 70%, of which 70% of the coefficient is to consider vibration, shock, partial load factors plus a.
Also, pay attention to whether there is proof requirements, explosive environments, explosion-proof sensors should be used.
2. Installation Notes
(1) Note that the horizontal adjustments, including the mounting surface and a set of pulling a single module to adjust the pressure level between the sensors.
(2) When soldering the sensor can not pass current, welding roof, ground to be connected on the scale body, welding floor, ground to be connected to the foundation, to prevent damage to the sensor.
(3) If the scale body conveying pipe, hose should be replaced, or connecting pipes as long as possible so that, in order to prevent them from eating the sensor's load caused the error.
(4) To weld a weight check station on the container to check. Place the container weights are generally no place, you need to weld a platform placed weight. Usually welded to the bottom of the container, the weight up and down for easy placement.
(5) The junction box must pay attention to moisture, excess use sealing plugs holes plugged. Junction box fitted on the outside, must be added to protect me, to prevent rain. Junction boxes in use due to damp conditions caused by a fault has occurred, and therefore must be taken seriously enough.
3. Commissioning notes
(1) Before commissioning sure to check whether each pull of the pressure sensor support screw top nut has been loosened, Detector shaft sleeve is in a free state, otherwise, would lead to considerable error, can not even weighed.
(2) When debugging, to check each parameter factory setting meets the actual needs, especially the "boot cleared" parameter, the factory is generally set to "boot automatically cleared" the best change in the container scales "Disable boot automatically cleared" to prevent blackouts due to other reasons, boot again, the material weight of the container is cleared and lost.
(3) The range is set to pull the pressure sensor does not refer to a nominal total load, not including the weight of the container itself, but should be based on the maximum material weighing, select from sub-degree and sub-degree specification values ??greater than or equal to the maximum weighed as a range.
(4) Weighing Display supply voltage must meet the requirements, such as voltage instability, beyond the permitted range, it will cause the digital shift. The best use of power supply.
Because electronic weighing system consisting of pull pressure sensor facilitates the weighing process automation, ease of computer networking, which in the chemical industry is bound to be more widely used.
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