智能差壓變送器是在普通壓力或差壓傳感器的基礎(chǔ)上增加微處理器電路而形成的智能檢測(cè)儀表,壓力或差壓變送器的精度為0.1 級(jí),量程范圍為 100:1 或 50:1,時(shí)間常數(shù)在 0 ~ 36s 可調(diào),儀表的電壓范圍為 15 ~ 36VDC,正常工作電壓為 24VDC,兩線制儀表,輸出電流 4 ~ 20mA,一般使用 HART 通訊協(xié)議。
智能差壓變送器的主要特點(diǎn)
可通過(guò)軟件對(duì)傳感器的非線性、溫漂、時(shí)漂等進(jìn)行自動(dòng)補(bǔ)償??勺栽\斷,通電后可對(duì)傳感器進(jìn)行自檢,以檢查傳感器各部分是否正常,并作出判斷。數(shù)據(jù)處理方便準(zhǔn)確,可根據(jù)內(nèi)部程序自動(dòng)處理數(shù)據(jù),如進(jìn)行統(tǒng)計(jì)處理、去除異常數(shù)值等。
智能差壓變送器的安裝方法及地點(diǎn)選擇
智能差壓變送器的安裝有多種方式,目前經(jīng)常用到的有以下三種。
A、直接管道安裝方式,這種安裝方式簡(jiǎn)單,用材少。
B、法蘭安裝,主要應(yīng)用于液位測(cè)量,利用液體的靜壓力對(duì)液位進(jìn)行測(cè)量。
C、支架安裝(管裝平支架),大多采用此種安裝方式,安裝維護(hù)方便,以往在露天的位置使用儀表箱作為保護(hù)智能差壓變送器免遭粉塵、雨淋,但現(xiàn)在的智能差壓變送器的防護(hù)做的很好,防護(hù)等級(jí)在 IP65,工作的環(huán)境溫度-40~+75℃,耐震動(dòng)、防塵、防雨,5年免維護(hù)。
智能差壓變送器的接線
目前,智能差壓變送器更多的用于 DCS 控制系統(tǒng)中,在現(xiàn)場(chǎng)安裝的智能差壓變送器均帶有 4 ~ 20mA 輸出和數(shù)字通訊功能,通過(guò)屏蔽電纜連接到現(xiàn)場(chǎng)電力室模件柜 AI 模件的輸入端。
手操器使用非常方便,可以在現(xiàn)場(chǎng)電力室內(nèi)的 DCS 模件柜相應(yīng)的端子上使用。通過(guò)手操器,可以檢查和設(shè)置智能差壓變送器的零點(diǎn)、量程、變送器工作點(diǎn)的溫度、工程壓力單位的選擇,如 Pa、Bar 等工作情況,例如某一壓力點(diǎn)的零點(diǎn)或量程需要改變,在電力室就可以通過(guò)使用手操器輕松改變。
Intelligent differential pressure transducer is an intelligent measuring instrument which is formed by adding microprocessor circuit on the basis of ordinary pressure or differential pressure transducer. The precision of pressure or differential pressure transducer is 0.1, the measuring range is 100:1 or 50:1, the time constant is adjustable from 0 to 36s, the voltage range of the instrument is 15-36VDC, and the normal working electricity. Pressure is 24VDC, two wire instrument, output current 4 to 20mA, generally use HART communication protocol.
Main features of intelligent differential pressure transmitter
The nonlinearity, temperature drift and time drift of sensors can be compensated automatically by software. It can be self-diagnostic. After power-on, the sensor can be self-checked to check whether the various parts of the sensor are normal and make a judgment. Data processing is convenient and accurate, and data can be automatically processed according to internal procedures, such as statistical processing, removal of abnormal values, etc.
Installation and location selection of intelligent differential pressure transmitter
There are many ways to install the intelligent differential pressure transmitter. There are three kinds of frequently used ones.
A, direct pipe installation, this installation is simple and less material.
B, flange installation, mainly used in liquid level measurement, using the static pressure of liquid to measure liquid level.
C. Bracket installation (pipe-mounted flat bracket), mostly using this installation method, easy installation and maintenance, in the past in the open-air position as a protection of intelligent differential pressure transmitter from dust, rain, but now the intelligent differential pressure transmitter protection done very well, protection level in IP65, working environment temperature - 40 ~ 40 It is resistant to vibration, dustproof and rain proof for 5 years.
Wiring of intelligent differential pressure transmitter
At present, the intelligent differential pressure transmitter is more used in the DCS control system. The intelligent differential pressure transmitter installed in the field has the function of 4-20 mA output and digital communication. It is connected to the input of AI module of the module cabinet of the field power room through shielded cable.
Manipulator is very convenient to use, can be used in the field power room DCS module cabinet terminal. Through the manual manipulator, can check and set the intelligent differential pressure transmitter zero, range, transmitter operating point temperature, engineering pressure unit selection, such as Pa, Bar and other working conditions, such as a pressure point zero or range needs to be changed, in the power room can be easily changed by using the manual manipulator.