I apologize for non-construction nature of this question. But it is electrical in nature and the family needs the dryer. I am attempting to diagnose the igniter in a gas cloth dryer. The website, Repairclinic.com, has very good information about repairing the dryer and it says to test the igniter’s continuity in ohm.
I don’t know how to use multimeter but I bought one anyway from HD. Sperry is brand name. According to instruction and other instructive websites, I think I got the right measurement. Here’s what I did. One tester in common plug. Other tester in a plug with ohm sign. When two contacts are separate, reading is 1. When contacts are touching, the reading is 0. So far so good. When I test the igniter, the reading is .055. Does this mean non-continuity? By the way, the dial was set to arrow in the ohm area.
The igniter is an element that ignites the gas and I am trying to see if it is burned out. I don’t know enough to give more information.
Would you also recommend a simple digital multimeter for a home owner and accompanying instruction book? Something like ohm, resistance and impedance for dummies. I found some instructional websites for using the meter but I am hoping there is one resource that explains the use of multimeters in everyday language. Thank you in advance.
Replies
Radio Shack may have a multimeter book for you.
Measuring resistance can be tricky. When the two probes aren't touching the reading should indicate "infinity" somehow. Study the meter to see how they're doing that (perhaps with an "out of range" indicator). When the two probes are touching you should get zero resistance, or darn close to it.
If your test of the igniter is really getting 0.055 then that's darn close to zero, indicating continuity. But double check that there's not a "K" or "M" on the display indicating that you're really reading K ohms or Meg ohms.
As a test, measure the resistance of a light bulb. Not sure exactly what you'll see, but it should be a few tens of ohms.
Oh man, if I did not know better would have thought I posted this (as a troll) after the good response I got from the 'buried extension cord' thread <G>
k1c:
which model of sperry? Many of them have multiple ohm settings, a '1' open circuit means you have it set on a low scale, the 0.055 (55 millioohms) does mean pretty good continuity (for ref, 55 milliohms is about 12 feet of 16 AWG wire, or just a few inches of nichrome).
Edit: What Dan said, only when you measure a light bulb cold it will be about 10 ohms for a 100 W bulb, 25 ohms for a 40 W bulb.
Edited 6/10/2008 4:53 pm ET by junkhound
yes, you are measureing the resistance in the wire, it is not an open cicuit
if it's a digital read out be sure to look at all the indications on the screen. Sometimes 1 ohm is read when in actuallity it's 1 kilo-ohm or > which is basically the same as an open.
Thank you all for the replies. LOL, I am still confused. Thank you but this time I will just test the parts the hard way, connecting them back and see if they glow, ignite the gas, etc. From your replies I get a feeling that I can't just test ohm continuity or other measurements without knowing the test requirements of the material itself.
I thought I had it because I read in some website that said 1 means infinity, or no continuity, and 0 means continuity. It doesn't seem as simple as that, although I wish it was that simple. Anyway, thank you.
>1 means infinity, or no continuity, and 0 means continuity<
for logic circuits, yes.
Keep working at the Multimeter, it's a valuable tool once you figure it out. when you're reading resistance (ohms) the lower the number the easier the electrons move and the higher the number the harder it is for the electrons to move. An ideal loop of wire with perfect connections will give you 0 ohms. Take a reading across a serviceable light bulb and you won't get 0 but it's still useable. Wet your fingers and hold the probes in each hand see what your body's resistance from finger tip to finger tip is.
You're right, knowing what you should expect to find is just as important to having the tool and the knowledge of it's use.
http://www.repairclinic.com/0003.asp
Check these guys out. They have great tips for all appliances with troubleshooting help.
“Some people wonder all their lives if they've made a difference. The Marines don't have that problem.” Reagan....
Failure is the condiment that gives success its flavor. -Truman Capote
I need to read better, you are already on the site.
“Some people wonder all their lives if they've made a difference. The Marines don't have that problem.” Reagan....
Failure is the condiment that gives success its flavor. -Truman Capote
I meant all this to j1c....
Head still buried......
“Some people wonder all their lives if they've made a difference. The Marines don't have that problem.” Reagan....
Failure is the condiment that gives success its flavor. -Truman Capote
You better get back in the tub w/Marty..LOLSpheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
"We strive for conversion,we get lost in conversation, and wallow in consternation. "Me.
ROAR!
Everytime I turned around John's name appeared. Turned to rectify that, wham, it showed up again, LOL
I should have deleted everything and went home.........
“Some people wonder all their lives if they've made a difference. The Marines don't have that problem.” Reagan....
Failure is the condiment that gives success its flavor. -Truman Capote
you better put the beer down & step away from the keyboard
ROAR!!
I wish it were a beer. Probably be better if I admit that and shut my soup cooler.....
I am at work trying to get through the night......
Only have 13 hours to waste.
“Some people wonder all their lives if they've made a difference. The Marines don't have that problem.” Reagan....
Failure is the condiment that gives success its flavor. -Truman Capote
Wife threw you out of the house again, eh?
It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May
LOL!
Got a spare bed?
“Some people wonder all their lives if they've made a difference. The Marines don't have that problem.” Reagan....
Failure is the condiment that gives success its flavor. -Truman Capote
You don't necessarily need a value. You are rough trouble shooting.
As John said look at the meter display. Observe what it looks like when the leads do not touch. This is called an open circuit or broken.
Now touch the leads together. This is a closed circuit. The display should have changed to zeros.
For you, in troubleshooting components, closed is good. All zeros in the display.
That is a good site you are on. Using an ohm meter is safer than troubleshooting live if you are unfamiliar with the equipment and electricity. Be sure to unplug the equipment.........
“Some people wonder all their lives if they've made a difference. The Marines don't have that problem.”
Reagan....
Failure is the condiment that gives success its flavor.
-Truman Capote
If I am not mistaken you have an ignitor with continouity but has high enough resistance that the current draw is low enough that don't allow the gas coils to open.It has been a while, but I think that I saw some comments by DanO to that affect. He operateshttp://www.appliance411.com/.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
If I am not mistaken you have an ignitor with continouity but has high enough resistance that the current draw is low enough that don't allow the gas coils to open.
That is a good point.....
“Some people wonder all their lives if they've made a difference. The Marines don't have that problem.” Reagan....
Failure is the condiment that gives success its flavor. -Truman Capote
you wrote:
"When I test the igniter, the reading is .055. Does this mean non-continuity? By the way, the dial was set to arrow in the ohm area."
Sperry meters and some others use scales with ohm ranges of
200 ... this is most likely the scale you are using with your meter and it will read anything between 0 and 200 ohms
2K
20K
200K and higher
you read .055 which IS continuity but with a resistance of .055 ohms if your igniter was broken your meter display will just be blank, the same as if you held the meter probes apart from each other (or infinity),
if your igniter was SHORTED you would read 0, the same as touching the probes together..... which is continuity or NO resistance.
based on your struggles I would say that your igniter still has some life in it and the dryer problem is elsewhere, perhaps a thermal cutout in the exhaust or a broken wire to the igniter.
BTW electricians do not use the terms interchangeably ,
continuity and resistance are two different things.
but I thought it would be helpful for you if I did not split hairs this time :)
and here is a little movie from youtube about multimeters:
http://www.youtube.com/watch?v=KzjMIcER4EU
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I had a similar problem. I took the panel off the bottom front. Then I removed
the lint filter cover.
this gave me access to the igniter and gas regulator. Turned on the dryer and
looked at the igniter to see if it got white hot,it did. No gas. Solution was new
solenoid coils. Easy to change. Hope this helps.
Thank you all for replies. Yes, the repairclinic mentioned those possibilities. I wanted to test the igniter (an heating element so I assume I would be measuring resistance in ohm, and test for continuity for wires and switches?) so I don't just unnecessarily replace parts still working. The coils were said to be very hard to diagnose so I was more or less committed to replacing them, but I wanted to be sure the problem wasn't the igniter.
I do mean to learn the multimeter. I never needed it just doing house wiring, but now that I got into the appliance, I see how I may use it. The clinic said I should test the igniter's continuity in ohm and I thought the multimeter would have a dedicated button that says ohm, but I got confused by the different values that I can choose. The 2k to 200k settings seem to move the decimal point around but only the setting with the arrow going through the line seem to give me .055 and stay stable. Other settings jumped all over the range. I assume this is because I don't know what to look for in the igniter. This will be my next research goal. Again, thank you everybody for the information.
When you're measuring resistance it's common for the readings to jump around if you just hold the test probes in place. It's best to use alligator clips so the slight motion of your hands doesn't affect the reading.The "arrow through the line" sounds like it may be a setting specifically for checking continuity. Check your manual.
It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May
When you're measuring resistance it's common for the readings to jump around if you just hold the test probes in place.
It would be difficult to move the probes around enough to make any measurable difference in the reading on the display - unless you are completely disconnecting them. This really is not a problem that happens. If the last digit of the display is "jumping" that is an issue with the meter - it's between a quantizer step or the hysteresis on the meter is too low.
difficult to move the probes around enough to make any measurable difference in the reading on the display
Actually pretty easy. Even with the old moving coil meters, could use an ohm meter as a lie detector back in high school (1950s).
Hand held probes would go from say 50 kohms to 48 kohms due to increased pressure and slight perspiration when someone lied.
Hand held probes would go from say 50 kohms to 48 kohms due to increased pressure and slight perspiration when someone lied.
I agree with that - but holding a probe against a soft permeable surface like flesh is different than holding the probe against a hard metal contact. If the subject is a hard metal contact that is reasonably clean, it's fairly easy to maintain good contact, in my experience.
hard metal contact
agree
When you're measuring below one ohm the contact resistance is a significant factor. Slight pressure changes can make a big difference.I got my first multimeter when I was 12. Put it together from an Eico kit. I know of which I speak.
It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May
When you're measuring below one ohm the contact resistance is a significant factor. Slight pressure changes can make a big difference.
Not really. If you are having that much trouble with varying resistance, it's more likely to be a bad connection in the lead set. The situation described rarely occurs in practice, in my experience, unless there is a problem with the lead set or the meter.
If you are seeing fluctuation in resistances below one ohm on a meter that cost less than a few hundred dollars (i.e. not a lab grade instrument), and the lead set is OK, the most common issue would be quantization error in the A/D converter on the meter. Measuring in the 1 ohm range is outside the range where the less expensive meters are accurate, and they will often have a digit or two of jitter at low ranges.
I got my first meter when I was 6 - one of the first electronics projects I completed, with my dad's help. It was an analog VOM - they didn't have digital multimeters back then. It's probably those early projects with my dad that led me to become an electrical engineer. I have designed lab and consumer grade testing equipment in my career, however, so this is a topic with which I am rather familiar
Edited 6/16/2008 10:45 am ET by woodturner9
Since you're so good at measurement, measure the resistance of the oxide layer on a lump of solder.
It is an ironic habit of human beings to run faster when we have lost our way. --Rollo May
measure the resistance of the oxide layer on a lump of solder.
Wow, you must be working on old equipment - lead based solder has not been used in electronics equipment for at least a decade.
Wow, you must be working on old equipment - lead based solder has not been used in electronics equipment for at least a decade.
Most aerospace equipment still uses lead based solder, the alternatives do not have nearly as good of reliability. Silver based stuff is a disaster in space.
Most aerospace equipment still uses lead based solder, the alternatives do not have nearly as good of reliability. Silver based stuff is a disaster in space.
It has been a while since I have worked on hardware destined for space. What kinds of problems arise from the use of silver based solder in space applications?
I'm going to chime in here only because some posters have given you confusing information. IMO!
For all Multimeters:
Ohms is the term for resistance to electrical current.
If you have zero ohms, it means you have no resistance. This is the same as having a direct connection between the two places you are measuring. This is called continuity. It indicates that there is a continuous path for the current to flow. It means electrical current can flow without resistance.
If you have infinite ohms, it means you have no connection, in other words no continuity. No current can flow.
Depending on your setting and the type of meter, the .055 could mean 55 ohms, 5.5 ohms, 550 ohms, 550,000 ohms - you get the idea.
Look at your setting and try to figure it out or ask somebody like your HD electrical guy, if you are lucky enough to find one with experience. In the big box electrical departments, they usually have people who have worked as electricians.
Make sure there is no power to anything that you measure for ohms.
When you are checking for continuity, you are checking for a low resistance vs. an open circuit. An open circuit will show up as infinity, so the fact that you are getting a consistent reading is a good indication that the ignitor is fine. There might be a failure mode where it has continuity but has the wrong resistance, but that is an unlikely thing to happen.
The manufacturer can tell you exactly what resistance you should expect if you want to check for sure.
Note that measuring resistance - especially low resistances - is fraught with errors. Unless you have a good multimeter (which in my book means your meter is yellow, says "Fluke" on it, and costs > $100 (there are other good meters as well)), your measurements are going to be misleading. If you are running into changing readings at low resistance ratings, it's more likely to be your meter than anything else.
One fun trick you can play on yourself is touching the contacts with your fingers, and adding in the resistance of your body.