溫度變送器是一種將溫度變量轉(zhuǎn)換為可傳送的標(biāo)準(zhǔn)化輸出信號的儀表。把溫度傳感器的信號轉(zhuǎn)變?yōu)殡娏餍盘枺缓笤龠B接到二次儀表上,從而可以顯示出對應(yīng)的溫度。目前,技術(shù)已經(jīng)非常成熟了,在各工廠中非常常見,主要可以應(yīng)用于石油、化工、化纖;紡織、橡膠、建材;電力、冶金、醫(yī)藥;食品等工業(yè)領(lǐng)域現(xiàn)場測溫過程控制;特別適用于計算機(jī)測控系統(tǒng),也可與儀表配套使用。
A temperature transmitter is a meter that converts a temperature variable into a standardized output signal that can be transmitted.The signal of the temperature sensor is converted into a current signal,which is then connected to the secondary meter so that the corresponding temperature can be displayed.At present,the technology is very mature,very common in various factories,mainly used in petroleum,chemical,chemical fiber;textile,rubber,building materials;electric power,metallurgy,medicine;food and other industrial fields on-site temperature measurement process control;especially suitable for The computer measurement and control system can also be used with the instrument.
溫度變送器需要定期進(jìn)行校驗嗎?
Does the temperature transmitter need to be verified periodically?
預(yù)熱器測溫采用的測溫元件有熱電阻和熱電偶,熱電阻測溫的范圍比較小,而預(yù)熱器的溫度達(dá)1000多攝氏度,因此,采用熱電偶測溫是.有效的手段。熱電偶分為一體化熱電偶和非一體化熱電偶。在我們公司多采用非一體化的熱電偶,通過溫度變送器將電信號轉(zhuǎn)變成為溫度信號傳遞給中央控制室,供操作員參考。非一體化熱電偶采用兩線制,通過溫度變送器連接公司的DCS系統(tǒng),返回中控室,在測量過程中,有的變送器受環(huán)境的影響較大,零點和滿點會發(fā)生不同程度的漂移,這就需要有效的手段對其進(jìn)行及時準(zhǔn)確的校準(zhǔn)。
The temperature measuring components used in the preheater temperature measurement have thermal resistance and thermocouple.The range of thermal resistance temperature measurement is relatively small,and the temperature of the preheater is more than 1000 degrees Celsius.Therefore,temperature measurement by thermocouple is the most effective means.Thermocouples are divided into integrated thermocouples and non-integrated thermocouples.In our company,we use non-integrated thermocouples to convert electrical signals into temperature signals through temperature transmitters for transmission to the central control room for operator reference.The non-integrated thermocouple adopts two-wire system,and is connected to the company's DCS system through a temperature transmitter,and returns to the central control room.During the measurement process,some transmitters are greatly affected by the environment,and zero and full points will occur to different degrees.The drift,which requires effective means to timely and accurately calibrate it.
校驗方法:
Calibration method:
1、校驗時,在輸入端接入電位差計,輸出信號為電動勢,在輸出端接上24VDC穩(wěn)壓電源并串接上標(biāo)準(zhǔn)電流表。
1.During calibration,connect the potentiometer to the input terminal,the output signal is the electromotive force,connect the 24VDC regulated power supply to the output terminal and connect the standard ammeter in series.
2、調(diào)零:反接信號輸入線,使電位差計輸出校驗現(xiàn)場室溫對應(yīng)電動勢,調(diào)整電位器Z,使電流表讀數(shù)為4mA。
2,zero adjustment:reverse signal input line,so that the potentiometer output verification site temperature corresponding to the electromotive force,adjust the potentiometer Z,so that the ammeter reading is 4mA.
3、調(diào)滿:正接信號輸入線,使電位差計輸出滿量程對應(yīng)電動勢,調(diào)整電位器S,使電流表讀數(shù)為20mA。(該電動勢為滿度電動勢減去室溫對應(yīng)電動勢后的值)
3,full:the signal input line is connected,so that the potential difference meter outputs the full range corresponding to the electromotive force,adjust the potentiometer S,so that the ammeter reading is 20mA.(The electromotive force is the value of the full-scale electromotive force minus the room temperature corresponding to the electromotive force).
注意事項:
Precautions:
1、接線時要注意極性,并且在通電預(yù)熱15分鐘后開始調(diào)校。
1.Pay attention to the polarity when wiring,and start tuning after 15 minutes of power-on preheating.
2、調(diào)校中以緩慢的速度輸入信號,以保證不產(chǎn)生過沖現(xiàn)象。
2.In the adjustment,input the signal at a slow speed to ensure that there is no overshoot.
3、在調(diào)整時不要用力過猛,防止擰壞。
3.Do not use excessive force during adjustment to prevent screwing.
4、調(diào)校前,要準(zhǔn)備好校驗記錄單,并查熱電偶在各校驗點的溫度/毫伏對照表或熱電阻溫度/電阻對照表,將調(diào)校溫度變送器需要的數(shù)據(jù)查出并填入已經(jīng)準(zhǔn)備好的數(shù)據(jù)記錄表中。
4.Before calibration,prepare the calibration record sheet,and check the temperature/millivoltal comparison table or the thermal resistance temperature/resistance comparison table of the thermocouple at each checkpoint,and adjust the data required by the temperature transmitter.Exit and fill in the prepared data record table.