CHEAP-O Multimeters often get a bum wrap by multimeter purists who constantly dwell on the fact that most inexpensive dmms have little or no input protection thereby affording a bevy of disaster case scenarios for the end user.
INPUT PROTECTION
“Cheap multimeters are dangerous”
You’ll be hearing this alot..what does it mean exactly ? Well in reality not very much.
Input protection isn't a four letter word., so no need to use expletives when mentioning it while talking about those CHEAP-O multimeters.
CAT RATINGS
IEC 61010 defines four distinct categories:
CAT IV Defined as “Origin of installation” Utility level and any outside cable run
CAT III Distribution wiring, including “mains” bus, feeders and branch circuits, permanently installed loads.
CAT II Receptacle outlet circuit, plug-in loads.
CAT I Protected electronic circuits.
Categories are defined by probability of over-voltage, the higher the over-voltage, the higher the category. All categories apply to low voltage only (<1000 V). Within each category (from CAT IV to CAT I) there are ‘working voltages’; 1000 V, 600 V, 300 V, 150 V, 50 V. The standard recognizes that within a given category, higher voltages require higher levels of protection.
Most CHEAP Multimeters are capable at safely managing CAT II standard household mains voltage whether Certified by an independent lab or not.
You might think a CAT II-1000 V multimeter is inherently “safer” than the CAT III-600 V instrument. However, even though the CAT II-1000 V rated working voltage is higher than the CAT III-600 V, the test impulse is the same. Both must withstand the same transient voltage. CAT III-1000 V (7.8 kV transient) is safer than CAT III-600 V (6.1 kV transient). But, CAT IV-600 V is the same as CAT III-1000 V. All multimeters are designed to measure nominal steady state voltages continuously while also being able to withstand a momentary high voltage spike or transient that hits the meter input without warning. It is important to note that today's multimeter is not designed to withstand a continuous overvoltage condition such as the utility service entrance or in many industrial settings.
Independent LAB Certification
UNDERWRITERS LABORATORIES
Underwriters Laboratories (UL) is a NRTL that is devoted to scientific safety testing. They work with electronics and batteries, chemicals, fire safety, and all the data and educational outreach that comes with it. Their goal is to scientifically inspect new products and technologies to ensure they are safe, effective, usable, and sustainable.
INTERTEK LABORATORIES (ETL)
Intertek is a laboratory testing service that works with materials across a wide variety of industries such as: food, chemicals, cosmetics, pharmaceuticals, electronics, toys, fuels, and a huge list of materials used in consumer and industrial goods. Intertek’s “ETL” certification mark is a verification seal of the “Electrical Testing Lab” founded by Thomas Edison.
CANADIAN STANDARDS ASSOCIATION
The Canadian Standards Association (CSA) tests, inspects, and certifies lab equipment, lighting, tools and construction equipment, information technology, personal protection equipment, appliances, and power or energy storage. The CSA does not work with Canada exclusively but with many different countries all over the world.
Don't be fooled!
CE
CE, you’ve probably seen the mark before. You’ll find this mark among certification labels on a myriad of electronics. But how many of us know what it is? For example, did you know that CE isn’t a certification at all?
The CE marking is a self-identifying mark that manufacturers place on their products to declare they are in compliance with the standards of Conformité Européenne (meaning: European Community). The CE mark identifies electrical products “said” to fall under the expectations set by European legislation.
However, the unfortunate downside for consumers is that some manufacturers will use this mark as a pseudo certification. Remember, CE is a self-proclaimed mark of compliance. There are no protocols, no testing, and no third-party validation necessary for a product to bare the CE mark. Any manufacturer can stamp it on their product as a claim to safety, but that claim only goes as far as the manufacturer’s word. In other words, the CE mark alone should offer no reassure to a consumer that the product is safe or efficient at what it does. So if you’re considering the purchase of a product that boasts nothing more than a CE mark, you should really reconsider ever getting it in the first place.
Determine the level of safety YOU require
You can easily spend hundreds of dollars on expensive multimeter gear and never need it. The average DO-It-Yourselfer or home hobbyist testing that Arduino circuit needn't break the bank on an expensive brand. Most often, those CHEAP-O Under 50$ Multimeters will do just as good a job at a fraction of the cost of their elitist brethren.
Check out our Multimeter TOP TEN and pick up a great multimeter at a great price today!
Great info, thanks Darren!