Kya apne kabhi socha hai, ki jab hum apni ungli se multimeter ko touch krke electric current ko check krte hai to hume shock kyu nhi lagta?
Ek multimeter bna hota hai 5 components se, cylindrical rod, resistor, neon lamp, spring aur ek metallic cap. Ab ye samjhte hai, ki ye sab cheeze milke kaam kese krti hai. Jab aap sirf tester ke insulated body ko pakad ke live wire se touch krte ho kuch bhi nhi hoga kyuki current ko aage flow hone ke liye koi medium nhi mila. Lekin jab aap tester ke upar lagi metallic cap ko touch krte ho to current app ke andar se flow hona shuru ho jata hai jisse humari body, earth aur live line mein ek connection banta hai aur centre mein lagi neon light bhi jalne lagti hai.
Per isse apko current kyu nhi lagata??
Ye isiliye hota hai, kyuki jab aap live wire ke sath ek tester ka contact krte ho toh current beech mein lagi cylindrical rod mein se hota hua ek resistor se nikalta hai, ye resistor ek mega tak ka hota hai. Jab current resistor ke through hoke nikalta hai to vo uski voltage ko 220v se gira kr 0.22 milliamps tak le ata hai.
Fir jab aap metallic cap ko touch krte ho to ye current apki body se hoke seedha earth tak jata hai. Aur iss level ka current human body ko bilkul bhi feel nhi hota. Ye khatarnak bhi ho sakta hai, agar multimeter ki voltage rating, live wire ki voltage rating se kam hai to. Isiliye humesha multimeter ki rating ko check krke hi use krna chahiye.
History
Pehla device jo multimeter ka predecessor mana ja sakta hai, wo 1820 mein aya—ek moving-pointer current detector, jise galvanometer kaha jata tha. Ye device electrical current ko detect karne ke liye design kiya gaya tha aur ye compass needle ko bhi hila sakta tha. Lekin ye bulky aur delicate tha, isliye fieldwork ke liye impractical tha.
Phir 1920 mein, British Post Office ke engineer Donald Macadie ne pehla multimeter banaya. Unhe is baat ka frustration tha ki unhe telecom maintenance ke liye alag-alag tools carry karne padte the, isliye unhone ek aisa tool banaya jo amperes, volts, aur ohms measure kar sake, jise unhone AVOmeter ka naam diya.
Pehla AVOmeter aaj ke digital multimeters ki tarah bulky tha. Lekin pehle dasak mein, iski size mein kaafi kami aayi, aur 1930s tak isne portable version aur additional features develop kiye.
Voltmeter ka evolution tab tez hua jab Westinghouse ne pehla Universal meter introduce kiya. Pehle AVOmeters sirf direct current (DC), resistance, aur 13 ranges mein voltage measure kar sakte the. “Copper oxide instrument rectifier” ke aane se, meter ne alternating current (AC) measure karne ki capability gain ki aur ranges ko 20 tak badha diya.
### Pehla Digital Voltmeter
Jaisa-jaisa technology aage badhi, analog voltmeter dheere-dheere out of date hone laga. Engineers 1950s se solid-state digital voltmeters ki soch rahe the, lekin ye technology 1970s tak hi practical ban payi. Semiconductors ke advancements ne is waqt designs ko feasible banaya.
Fluke 8020A duniya ka pehla successful handheld digital multimeter bana, jo voltmeter aur multimeter features ko mila kar field technicians ko aise troubleshooting capabilities diya jo pehle sirf lab specialists ke liye thi. 1977 mein launch hone par, ye technicians ke liye accurate, reliable, user-friendly, aur durable tha, jisne unki professional image ko bhi enhance kiya.
Is innovation ne Fluke ka focus bench test instruments se handheld electrical testing tools ki taraf shift kar diya. 1980s tak, 8020 aur iske successors ne tough work environments mein apni reputation bana li, aur ek million se zyada units beche, demanding technicians mein loyalty build ki.
Cutting-Edge Technology
Ye device ek aise daur mein launch hua jab technological advancements ho rahe the, jaise ki 1977 mein pehli baar fiber optic phone circuits ka service shuru hona. Fluke 8020A ne state-of-the-art electronics ka istemal kiya. Pehle ke components zaroori high performance aur low cost ko nahi de pa rahe the, isliye Fluke designers ne iski LCD display ke liye ek custom complementary metal oxide semiconductor (CMOS) analog-to-digital converter chip banayi.
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