Digital Multimeter Calibration Purpose The purpose of this procedure is to provide instruction for the calibration of digital multimeters (DMM). Scope All multimeters (multi-range instruments used to measure voltage, current, and resistance) are to be verified in calibration no less than once per year. Procedure Preliminary Instructions and Notes 1. Read this entire procedure before beginning the calibration. 2. Calibration shall be performed in an environment that conforms to Manufacturer Specifications. 3. The digital multimeter will hereafter be referred to as the Instrument Under Test (IUT). . Verify that the IUT is clean. 5. Visually examine the IUT for any condition that could cause errors in the calibration. 6. If any of the requirements cannot be met, refer to the applicable manufacturer manual. 7. If a malfunction occurs or a defect is observed while calibration is in progress, the calibration shall be discontinued and necessary corrective action taken; if corrective action affects a measurement function previously calibrated, the function shall be recalibrated before the remainder of the procedure implemented. Reference Material Applicable Manufacturers Manual or Brochures.
Specifications The specifications of the IUT are determined by the applicable manufacturer’s documentation. If the manufacturer’s documentation is not available, then the specifications identified in this procedure are used. Equipment Required The Standards listed below should be selected on the basis of their higher accuracy level when compared to the unit under test. Equivalent Standards must be equal to or better than the Minimum-Use-Specification. Minimum-Use-Specifications for Standards listed are 1/4 the accuracy required by the IUT. * Rotek Model 2500 Calibrator or equivalent * Diode Test Fixture Test Leads * Continuity Test Fixture * Capacitance Test Fixture * Thermometer * Hydrometer Set-Up Turn all power on (calibrator and the unit to be calibrated). Allow the instruments to stabilize for approximately 5 minutes. Conduct the tests in an ambient temperature of 25 ± 5C and a relative humidity of less than 80%. Note: If the IUT has an automatic ranging feature, then the function being checked (i. e. voltage, current, or resistance) must be verified in the variable range mode as well. Battery Replacement Replace the battery in the IUT and make sure the battery contacts are not dirty.
Detailed Procedure Display and Switch Test Turn the IUT on and verify that all LCD segments are working and not dim. Verify that the selector switch(s) is/are working properly. Make sure the Low Battery indicator is not showing. Resistance Check Connect the calibrator between the V/ohm and common input terminals of the IUT. Use the following chart to verify the resistance values. Step | Range | Input | Display | 1 | 200 ohm | Short | 00. 0 to 00. 5 | 2 | 2 k ohm | Short | 0. 000 to 0. 001 | 3 | 2 k ohm | 1 k ohm | . 998 to 1. 002 | 4 | 20 k ohm | 10 k ohm | 9,98 to 10. 02 | | 200 k ohm | 100 k ohm | 99. 8 to 100. 2 | 6 | 2000 k ohm | 1 M ohm | 998 to 1002 | 7 | 2000 M ohm | Open | 0. 10 to 00. 0 | Continuity Test 1. Select the continuity check function on the calibrator. 2. Connect the test leads to the V/ohm and common terminals of the IUT. 3. Momentarily short the test leads together and observe that the tone sounds. 4. Connect the test leads to the continuity test fixture between the 100 ohm test points. No tone should be heard indicating non-terminating connection. 5. Connect the test leads to the continuity test fixture between the 50 ohm set up.
The test tone should indicate continuity between the test points. DC Voltage Test 1. Use the calibrator to supply the correct DC voltage listed below. 2. Set the calibrator for a zero volt input. 3. Connect the calibrator output to the V/ohm and common input terminals of the IUT. Note: Connect the ground/common/low side of the Rotek 2500 to the common on the IUT. 4. With reference to the table below, select the IUT voltage range and set the calibrator output to the corresponding IUT input voltage. Test per the following chart and verify that the display falls within the limits given.
Step | Range | Input | Display | 1 | 200mV | 190mV | 189. 7 to 190. 3 | 2 | 200mV | -190mV | -189. 7 to -190. 3 | 3 | 2V | 0. 0V | -0. 001 to 0. 001 | 4 | 2V | 1. 9V | 1. 897 to 1. 903 | 5 | 20V | 19V | 18. 97 to 19. 03 | 6 | 200V | 100V | 99. 84 to 100. 16 | 7 | 1000V | 400V | 399. 3 to 400. 6 | AC Voltage Test Use the calibrator to supply the correct AC voltage in the following test: 1. Set the calibrator to 60 Hz. 2. Connect the calibrator output to the V/ohm and common input terminals of the IUT. Connect the ground/common/low side of the calibrator to common on the IUT. . With reference to the table below, select the IUT voltage range given in step 1 and set the calibrator output to the corresponding IUT input voltage. Verify that the display reading is within the limits shown. Step | Range | Input | Display | 1 | 200mV | 100mV | 99. 0 to 101. 0 | 2 | 2V | 1V | 0. 990 to 1. 010 | 3 | 20V | 10V | 9. 90 | 4 | 200V | 100V | 99. 0 to 100. 1 | 5 | 750V | 400V | 294 to 406 | DC Current Test Use the calibrator to supply the correct DC current listed in the table below: 1. Set the output of the calibrator to zero mA. 2.
Connect the output of the calibrator to the lowest current terminal (typically 200 mA) and common input terminal on the IUT. Note: Do not exceed the maximum current rating of the meter. Only test for values the meter is capable of reading. 3. With reference to the table below, select the IUT current range and set the calibration output to provide the corresponding IUT input current. Verify that the display reading is within the limits shown. Step | Range | Input | Display | 1 | 200? A | 190? A | 189. 7 to 192. 3 | 2 | 2mA | 1. 9mA | 1. 897 to 1. 923 | 3 | 20mA | 19mA | 18. 97 to 19. 23 | 4 | 200mA | 190mA | 189. 7 to 192. 3 | . Disconnect the calibrator and change the current terminal on the IUT to the highest setting (typically 10 A) leaving the common input terminal connected. 5. Use the following table to verify that the meter is functioning within the specified parameters. Step | Range | Input | Display | 1 | 10A | 1A | 0. 98 to 1. 02 | 2 | 10A | 5A | 4. 90 to 5. 10 | 3 | 10A | 9A | 8. 82 to 9. 18 | AC Current Test Use the calibrator to supply the correct AC current listed in the table below: 1. Use the following table to verify that the meter is functioning within the specified parameters. 2. Set the output of the calibrator to zero mA. . Connect the output of the calibrator to the low current input terminal (typically 200 mA) and the common terminal of the unit under test. Note: Do not exceed the maximum current rating of the meter. Only test for values the meter is capable of reading. 4. With reference to the table below, select the IUT current range and set the calibrator output to provide the corresponding IUT input current. Verify that the display reading is within the limits shown. Step | Range | Input | Display | 1 | 200? A | 190? A | 18. 27 to 19. 28 | 2 | 2mA | 1. 9mA | 1. 872 to 1. 928 | 3 | 20mA | 19mA | 18. 72 to 19. 28 | | 200mA | 190mA | 187. 2 to 192. 8 | 5. Disconnect the calibrator and change the current terminal on the IUT to the highest setting (typically 10 A) leaving the common input terminal connected. 6. Use the following table to verify that the meter is functioning within the specified parameters. Step | Range | Input | Display | 1 | 10A | 1A | 0. 97 to 1. 03 | 2 | 10A | 5A | 4. 87 to 5. 13 | 3 | 10A | 9A | 8. 77 to 9. 23 | Logic Test Use this procedure to test weather the logic function is indicating the correct state. 1. Set the IUT to the logic test mode and insert the test leads into the V/ohm and common terminals. 2.
Short the leads together and verify that the meter indicates a low logic state. 3. Set the calibrator to 0. 400 VDC and connect the meter to the output terminals. Verify that the meter indicates a low logic state. 4. Set the calibrator to 3. 500 VDC and verify that the IUT indicates a high logic state. Frequency Test 1. Connect an oscilloscope to a function generator to measure AC sine waves. 2. Set the function generator to output 10 VAC and use the oscilloscope to set the frequencies from the following table. 3. Connect the IUT leads to the V/ohm and common terminals on the IUT and to the ground and output of the function generator. . Verify the meter is displaying proper results from the table. Step | Range | Input | Display | 1 | Hz | 60 Hz @ 10V | 59. 4 to 60. 6 | 2 | Hz | 1 kHz @ 10V | . 990 to 1. 010k | 3 | Hz | 1 MHz @ 10V | . 990 to 1. 010M | Capacitance Test 1. Set the IUT to measure capacitance, insert the test leads into the V/ohm and common test terminals. 2. Connect the meter to the capacitance test fixture and use the following table to determine the ability of the IUT. Step | Range | Input | Display | 1 | Capacitance | 10 micro F | 9. 85 to 10. 15 | 2 | Capacitance | 1 micro F | . 985 to 1. 015 | 3 | Capacitance | 100 micro F | 98. to 101. 5 | Diode Test 1. Set the IUT to the diode check function and connect the test leads to the V/ohm and common terminals. 2. Connect the test leads to the diode test fixture and follow the steps in the proceeding table to verify diode test operation. Step | Range | Setup | Polarity | Display | Tone | 1 | Diode Check | Short | N/A | . 000 to . 001 | Yes | 2 | Diode Check | Si | Forward | . 800 to . 600 | Yes | 3 | Diode Check | Si | Reverse | 1. | No | 4 | Diode Check | Ge | Forward | . 300 to . 500 | Yes | 5 | Diode Check | Ge | Reverse | 1. | No | 3. Note: Some meters are not designed to emit a tone.
Multimeters Prerequisites: This lesson is designed so that no prior knowledge is required. Description: This lesson demonstrates and explains how to use both a digital and an analog multimeter. During this lesson, voltage, resistance, current, capacitance, and frequency are measured. This lesson also describes some of the more common features of a digital multimeter. Objectives: * Identify and describe the display area, the function switch, and the leads/jacks on a digital multimeter * Adjust the mechanical zero and interpret a reading on the voltage scale, and the resistance scale of an nalog multimeter * Given an expected measurement, set the function and range switches of an analog multimeter and adjust the zero on the ohms scale * Know how to use a multimeter for a variety of purposes including checking for continuity across a circuit, measuring resistance, current, frequency, ac and dc voltage, and capacitance * And use the hold button, relative button, range button, and min/max button on a dmm Ammeters, Meggers, and Wheatstone Bridge
Prerequisites: This lesson is designed for participants familiar with AC and DC theory, electrical safety, and electrical print reading. A basic understanding of electronic devices and circuits is recommended. Description: This lesson describes Wheatstone bridges, megohmmeters, and clamp-on ammeters. This lesson provides examples of the use of these instruments, identifies their components, and defines their functions.
This lesson also describes safety and selection considerations for their use, describes how to set up the instruments, how to connect them to the systems under test, and how to take and read measurements. This lesson describes how to take a resistance reading of a Three-phase AC motor with a megohmmeter, how to set mechanical and electrical zero on a Wheatstone bridge, and how to interpret a Wheatstone bridge reading. This lesson also defines the “record” and “lock” features of a clamp-on ammeter and describes how to modify the range of the meter for the best results. Objectives: Explain the use of a megger, identify its basic components and define its function * Describe the safety and selection considerations for using it, and describe the procedures for setting it up * Know how to attach the leads to the system and take a reading of a three-phase ac motor * Define a bridge circuit and identify the components and function of a Wheatstone bridge * Describe how to take a reading with a Wheatstone bridge and interpret it * Identify the components, range, function, and safety and selection consideration for a clamp-on ammeter * Describe the procedures for setting up a clamp-on ammeter, know how to take a reading and modify the range 1. Top+You 2. Search 3. Images 4. Maps 5. Play 6. YouTube . News 8. Gmail 9. Documents 10. Calendar 11. More 1. 2. 3. 4. 5. 6. 7. 8. | Top of Form Bottom of Form 1. 2. Sign in Books No eBook available ISA| A1Books. co. in| Rediff Books| Flipkart| Infibeam| | Find in a library| All sellers »| | 4 ReviewsWrite review| Calibration: A Technician’s Guide By Mike CableTop of Form | | | Bottom of FormAbout this bookMy libraryMy HistoryBooks on Google Play Pages displayed by permission of ISA. Copyright. | | | Samsung Series 9 Notebook Top of Form Bottom of Form Samsung recommends Windows 8. Print This Operating System| Operating System| Genuine Windows® 7 Home Premium (64-bit)| Display| Screen Size | 13. ” SuperBright Plus widescreen display| Resolution| LED HD| Brightness| 400 nits, up to 16 million colors, HD LED Backlit anti-glare display| Memory| Standard System Memory| 4GB DDR3| Max. System Memory| 8GB| Storage| Hard Drive Capacity | 128GB SSD| Graphics| Graphics Chip | Intel® HD Graphics 3000| Multimedia| Speakers | 3 W Stereo Speaker (1. 5 W x 2)| Web Camera | 1. 3 MP HD| Connectivity| Wireless LAN | 802. 11 b/g/n WiFi| Bluetooth | Bluetooth V3. 0 High Speed| I/O Ports| HDMI | Yes| USB Ports | 2| Headphone Out| Yes| Microphone In| Yes| Multi Card Slot| 1 MicroSD| RJ45 (LAN) | Yes| Input Devices| Keyboard | 81 Key| Touch Pad | Yes| Power|
AC Adapter| 40 W| Design| Color | Black| Dimensions| Dimensions (W x D x H) | 12. 9″ x 8. 9″ x 0. 62″ ~ 0. 64″| Weight| Weight| 2. 88 lbs. | Warranty| Warranty| 3 Year| HP Pavilion g6-1A69US test unit has the following configuration: * 15. 6-inch glossy 720p display (1366×768 resolution) * Windows 7 Home Premium 64-bit * Intel Core i3-380M dual-core processor (2. 53GHz, 3MB cache, 35W TDP) * Intel HM55 chipset * Integrated Intel HD graphics * 4GB DDR3-1066 RAM (2x 2GB; supports up to 8GB – 2x 4GB) * 500GB 7200RPM Seagate hard drive (ST9500325AS) * 802. 11n wireless network adapter (Atheros AR9285) * No internal Bluetooth * Integrated webcam Built-in tray-load DVD burner (hp DVDRAM GT31L) * One-year limited warranty * 6-cell Li-ion battery (10. 8V, 4200mAh) * Weight: 5. 5 lbs. * Dimensions: 14. 72 x 9. 65 x 1. 20~1. 42 inches. Laptop buying guide * CNET UK * Reviews * Computers * Laptops Laptop buying guide Computers If you believe the headlines, the first rule about buying a laptop today is to forget about buying a laptop today. These bloated, annoying, space-hogging gadgets are apparently painfully obsolete compared to modern, sleek and sexy tablet computers. But just hold on a minute! Laptops still outsell tablets four to one, and sales in 2012 are expected to top a quarter of a billion worldwide for the first time ever.
Laptops are faster and more powerful than tablets, have convenient full-size keyboards, are easy to connect to printers and cameras, and can glide between work and games in a flash. (Plus they can all actually run Flash. ) If you want an affordable, practical digital all-rounder, laptops come in an array of shapes, colours and prices that make flat, grey tablets look boringly identikit. There are laptops for students, laptops for artists, even laptops for mountain climbers. The only drawback to this variety is that it can be all too easy to end up with a computer that’s either underpowered or overpriced for your needs. First things first You’ll need two things when shopping for a laptop: a clear idea of what you want to do with it; and a firm budget. The good news is that all new laptops ill be fine for checking email, surfing the Web wirelessly, working on office documents, and enjoying your photo and music collections. Where things start to get trickier is if you’re heavily into gaming, want to watch (or edit) HD video or need a computer that works well away from power sockets or in extreme conditions. Fix a budget before you start browsing — although leave a little wriggle room for extras like a laptop sleeve, software, a separate mouse and possibly an external hard drive. The basics Laptops come in three categories. At the small and portable end are ultra-lights, designed for stressed-out executives formatting Excel spreadsheets on the Heathrow Express.
Not to be confused with budget netbooks (we have a whole buying guide just for them), ultra-lights tend to be nicely designed, a little sluggish and shockingly expensive. Their screen sizes range from around 11. 5 inches to 13 inches. The next step up is everyday laptop computers, sometimes called notebooks, with screens from 13 inches to 15 inches. This is the sweet shop for laptops, where the most are sold and prices are keenest. Notebooks are light enough to carry occasionally and can usually manage half a day’s work away from power, but budget ones often lack style, speed and build quality. The final category is multimedia (or desktop replacement) laptops.
These monsters have screens up to 17 inches (and sometimes even larger), and come packed with smart graphics cards, super-fast processors and lots of memory. They’re the first choice of gamers, graphic designers and anyone who wants the power of an old-school desktop squeezed into a portable body. Well, we say portable, but these laptops can be heavier than a case of duty-free and bulky enough to need a Business Class seat to themselves. Windows or Mac Switch on the telly and it seems that everyone using a computer has an Apple Mac, except perhaps those hardcore hackers you see surrounded by monitors, empty pizza boxes and Star Wars figurines.
In real life, however, the choice is not quite so clear-cut. Macs are built well and age slowly but cost at least two to three times as much as the cheapest Windows machines. Even at those prices, the most affordable MacBooks have cramped screens and some performance limitations. Windows computers offer more choice and lower prices, but you’ll need to stay on top of upgrades and security to get the best from them. When shopping for a PC laptop, insist on Windows 7 software. It doesn’t really matter which version, although anything running the Starter Edition is actually a netbook rather than a laptop — hop over to our netbook buying guide for more info. A bigger decision is what brand to buy.
Unlike desktops, where even no-name companies can make great computers, the technical challenge of squeezing hundreds of components into a tiny case favours multinationals. Stick with top electronics brands (such as Sony, Samsung, Panasonic and Toshiba) or laptop specialists (Acer, Asus, HP/Compaq, Dell). Some retail chains also have ‘in-house’ brands that can be good value, if a bit plasticky. Tech specs Laptop specifications change all the time and consist of a brain-melting alphabet soup of letters and numbers. In general, there are three things to consider: the processor; memory (RAM); and storage. You can ask about other key components, like the graphics card and graphics memory, but don’t expect to understand the answer — check the model online if this is important to you.
Processors are virtually all dual-core these days, and are usually made by either Intel or AMD. There’s little to choose between the two, although AMD silicon tends to be found in cheaper machines. Intel chips get more powerful as their model number increases (ie. an Intel Core i5 chip is faster than an Intel Core i3). Processor speed, quoted in GHz, affects how fast it can crunch numbers. Anything above 2GHz is fine for everyday use, but gamers and video fiends should look for higher numbers, and especially for Intel’s Turbo Boost feature. RAM is the other thing that affects how fast your laptop runs. 2GB is an absolute minimum these days — and step up to 4GB (or even 6GB) if you can possibly afford it.
Hard decisions Hard drives generally range between 250GB (miserly) to 1,000GB (1TB, gargantuan). These determine how much data, including music and video, you can store on your laptop. Always buy a little more storage than you think you’ll need, but don’t bankrupt yourself. External drives are getting cheaper all the time, and space-saving cloud services are increasingly popular. Apple’s MacBook Airs, and some high-end Windows laptops, have fancy solid state drives that are faster, tougher and use less power. They’re also achingly expensive and come in smaller capacities. Screen and build quality Always try to get your hands on a laptop before you buy.
Start by looking at the screen indoors and — if possible — near a window or outside. You’ll probably find that Apple and Sony screens have the brightest colours and best contrast. If you do have to buy from the specs alone, look for LED backlighting and Full HD for the best resolution, found on pricier machines. ‘3D’ is a buzzword right now and 3D laptops are already trickling out. While games and films can look stunning in 3D, the technology is still fairly young, fairly expensive and suffers from low levels of brightness and sharpness. Consume at your own risk. Don’t underestimate the importance of a good keyboard, trackpad or navigation nipple.
Look for dedicated keys for mail, Web and especially media controls — they all make smaller keyboards easier to use. Open and shut the case a few times and hold it in both hands. How heavy is it? Does it flex or creak? How strong does it feel? While it’s hard to beat Apple for solidity and design, all the big brands have premium metal-bodied models, and Panasonic even has fully waterproof and toughened Toughbooks. In and out The best laptops have a choice of connectors, including multiple full-speed USB ports, HDMI sockets for linking to media systems and memory card readers. Some laptops will have DVD or even Blu-ray players, although these add weight and suck power.
A built-in webcam is great for Skype, Facebook or FaceTime video calls — don’t worry about its resolution. Spare a thought for the battery powering all this techno wizardry. Manufacturers’ battery life figures are a rough guide, but take them with a pinch of salt and don’t expect to achieve day-long use without resorting to a socket. If you simply must have mobile freedom, choose a laptop with a replaceable battery and buy a spare immediately — they can be hard to find a year or two down the road. Ultrabooks Finally, keep an eye out for ‘ultrabooks’, a new term coined by Intel to describe ultra-thin PC laptops rivalling the MacBook Air. Expect machined etal cases, solid state drives and even touchscreen displays to make the most of new finger-friendly Windows 8. You can read our reviews of some of the first ultrabooks, including the Asus Zenbook UX21, the Toshiba Portege Z830 and the Acer Aspire S3. From G. NATARAJAN R-52/2, Thermal Nagar -11, Thottilpatty, MetturDam -636406. To THE BRANCH MANAGER, State Bank of India, Mettur Dam-636401. Sir, Sub: Issue of new cheque book – change in address – intimation :-reg Ref :Acc No. 11194737290 I came to know that SBI is issuing new cheque books to customers at their last recorded address. I request you to kindly issue the new cheque books at my present residing address given below. G. NATARAJAN,
R-52/2, Thermal Nagar -11, Thottilpatty, MetturDam -636406. Thanking You Yours faithfully (G. NATARAJAN) From G. NATARAJAN R-52/2, Thermal Nagar -11, Thottilpatty, MetturDam -636406. To The Principal, Apple Perks International School, Mettur Dam-636452. Respected Madam, Sub: Filing of Income Tax return for the year 2012-13-Bonafide Certificate – Requested – Reg:- I have to file Income Tax return for the year 2012-13. Kindly issue the Bonafide Certificate to the payment of School fees for my daughter N. S. Rithika studying Pre KG in your School for the year 2012-13 please. Yours faithfully (G. NATARAJAN) CLEANLINESS Introduction:
Cleanliness is one of the good qualities. It is a part of our civilization. A man of dirty habits is far from civilization. So, with the progress of civilization man cleans himself more and more. He cleans his body. He cleans his mind and heart. He cleans all his action and manners. he cleans his soul. This will lead him to the highest form of civilization. But on the cleanliness of body, depend all other cleanings. Hence, cleanliness is considered so important. Usefulness: If we clean our bodies and limbs we will be free form many kinds of disease. Clean food cooked in the clean pot and served in the clean dishes, will give us health and happiness.
If we clean our bodies regularly, our complexion will be brighter. We will look fit and smart. If we wear clean dress our mind will be happy. Cleanliness gives us a cheerful mind. We are more interested to write on a clean khata than on a dirty one. Hence, we write more and better. We like to read clean books. Hence, we read more and understand better. So, cleanliness brings us progress and improvement in all fields of activities and in all spheres of life. By cleanliness of body and limbs, cleanliness of all our articles of use, cleanliness of our dwellings and soul, we gradually move towards divinity. Hence, there is saying. “Cleanliness is next to Godliness”. How to keep clean:
In order to keep ourselves neat and clean, we should properly take daily care of ourselves, of our articles of use, of our dwellings and surroundings and of our neighborhood. We should clean our teeth and tongues two times a day in the morning and before going to bed. Beside, we should clean our mouth properly before and after each meal and each tiffin. We should was our bodies two times a day with soap and water. We should clean our cloth and shirts with washing soap everyday at the time of bath. We should sweep our house off all dirts. We should remove the filth and rubbish into a pit, dug out at a distance for this purpose. We should clean our beddings and lay them exposed to sun and air. We should look to the proper drainage and sanitation work of our house and the surrounding.
We should wash our house and furniture with soda and water once a week. We should advice our neighbors to be neat and clean. Because we cannot be perfectly clean, if our neighbors are dirty. We should wash our latrines and urinals everyday with dettol and phenyl. We should get our hair cut and our nails pared at proper intervals. These are some important to keep ourselves neat and clean. Conclusion: it is really a matter of sorrow that most of our students are dirty. It is very sorrowful when we think that they keep dirty. Though they read science and hygiene. To make our countrymen neat and clean we should put ideals in the public institutions. So, our students should learn to keep themselves clean regularly.