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multimeters best??? #5672 12/01/01 10:22 PM
Joined: Nov 2001
Posts: 23
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rayh78 Offline OP
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Always have used old analog type test meter. just got a new Fluke T5-100 digital meter with the jaws.
First thing I noticed is when you put the test leads into a outlet to check if current it reads the same if you switch the test probe. Red probe to hot or red probe to neutral. Old anolog meter will try to go backward if hot and netural are reversed.
Also cant seem to read anything with the jaws only the test leads.
should I try a different brand or go back to old style?????

Thanks

Work Gear for Electricians and the Trades
Re: multimeters best??? #5673 12/02/01 01:43 AM
Joined: Oct 2000
Posts: 2,721
Scott35 Online Happy
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You had an Analog meter's needle swing backwards on AC? There should not be any difference of needle movement with an Analog meter on AC, whether the red probe is on the "Neutral" side or on the "Hot" side when doing a Voltage test.

Current tests would need the load current to flow through the Meter, then the load, but once again the polarities on AC would not matter [unless it's listed to have "Line" current in at one point / probe, then "Load" current out the other point / probe].

DC voltages will cause an Analog needle to swing "Into The Negative", or simply swing to the left side of the "zero" mark if polarity is reversed on a Voltage test. Same goes for an Ampere flow-through test; if the current is flowing in the opposite direction than the needle's deflection registers, it will of course swing to the left.

Digital Meters will show a "-" when doing Voltage tests, or flow-through amperage tests, with reversed polarity on the probes on DC systems.

AC tests will not show any polarity preference.

Be sure that you are setting the selection dial to the correct setting for the test you are performing. This is the same for Analog or Digital meters. Testing under incorrect settings will result in inaccurate readings, or misleading results [such as polarity swings].

If you are unsure of the selection points to use on your meter, repost another message to this thread with the symbols / indications shown on your meters, and we can give the equivalent meanings.

As far as the "Jaws", those are for amperage readings from only one conductor, and almost always for AC only.
Clamp the jaws around a single conductor to read the amperes.
Once again, be sure the meter is in the correct setting for amperage before clamping around a conductor. Start with the highest value, then work down to a lower value [if needed].

If the Ammeter probe ["Jaws"] are a separate unit which you connect to the meter, be sure to observe the connection methods and the "Scaling" figures.

Lastly, there's nothing wrong with using Analog meters - or Digital meters for that fact!
Digital meters have high accuracy, are simpler to use, easier to read, sometime more functions, and higher input Impedance - as compared to Analog meters [most commonly used Analog meters]. The High Z [input Impedance] can give you less/more than expected readings, so be aware of this situation. This is reffered to as "Low Loading Effect" for the meter.
Sometimes, the readings of an extremely high Z meter are interesting! [I'll keep out of this, or the message will become too long!].

Anyhow, Analog meters are great to observe conditions as they change. The visual effect of a swinging needle expresses changes greatly!
Digital meters are great for convenience of use, ease of reading and multiple functions - if you get into that stuff [Capacitor tests, Diode tests, Transistor tests, Hz tests, etc.]. They also allow "Sample And Hold" and "Peak" values almost universally - where this is something only special type Analogs would have [spec Analogs would also have the advanced testing abilities I mentioned].

One nice thing about most mid-level Analog meters I have seen [$100 - $200 range] is a setting for dB!

My FET Analog meter [used at home only!] has settings for DCV [1 to 1KV], ACV [3 to 1 KV], dB [-20 to +12], DCA [100 microamps to 10 amps], and of course - ohms [X1 to X100K + a continuity ringer].
Meter's acuuracy / loading effect is:
DCV: 10 Mohm
ACV: 10 Kohm
DCA: 316 mV

I have two "At Home" Digital meters. One has all the typical DMM features, plus Capacitor, Transistor and Diode testing ports.
The other one is a True RMS meter, and includes the typical DMM features plus Capacitor tests, Diode tests, Hz tests, Temperature tests and a nice continuity tester [upto 200 ohms for a "beep"].
It's ranging can be selected to 0.001 values, which is nice.

Scott SET


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Re: multimeters best??? #5674 12/02/01 08:32 AM
Joined: Aug 2001
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pauluk Offline
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Scott has given a very comprehensive reply that just about covers all the major points. I'll just add my two cents worth....

I also use both analog and digital meters. I use digital for sensitive circuitry where high accuracy is important, but I still prefer analog for many day-to-day tasks.

As Scott mentioned, for house electrical work the high-impedance of a digital meter can give rise to some confusing readings, such as getting perhaps a 50 or 60V reading on a wire which is actually disconnected. (Without getting into the technical bits too much, this often happens where the wire runs a long distance with other wires which are hot.)

The clamp-on jaws won't work if you just put them around, say, an appliance cord, because at any given moment the currents in the hot and neutral are flowing in opposite directions and cancel out - It has to go around just one wire.

If you measure appliance current regularly, you can get a neat little adapter which connects between the plug and wall receptacle. This takes one side of the circuit straight through but brings the other into a plastic former around which you can clamp the jaws easily. Many have a second "x 10" section for measuring low currents.

I have one of these gizmos as an accessory to my Simpson 260.

Re: multimeters best??? #5675 12/02/01 10:21 AM
Joined: Aug 2001
Posts: 545
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aldav53 Offline
Member
Pauluk, where did you get the adaptor for measuring appliance current, and what is it called?


The Golden Rule - "The man with the gold makes the rule"
Re: multimeters best??? #5676 12/02/01 11:43 AM
Joined: Oct 2000
Posts: 3,961
Bill Addiss Offline
Member
Paul, Al,

I have something like that too. It came with an Amprobe tester kit years ago.
[Linked Image from amprobe.com]
On mine those top leads come off and there are 2 prongs to plug in a receptacle. The Red part on the bottom (remove BEFORE plugging in!!) comes off and it is a 2 prong receptacle. The Appliance plugs into it. One ring is 1x and the other is 10x

Look Here

Bill


Bill
Re: multimeters best??? #5677 12/02/01 08:33 PM
Joined: Aug 2001
Posts: 7,520
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pauluk Offline
Member
Bill,

From the pic and descripion, it looks as though yours is a little more versatile with the removable clip leads.

Al,

The one I have is similar in appearance with the two positions for x1 and x10, but it has a fixed 2 ft. cable to a molded plug/receptacle combination (standard U.S. NEMA 5-15).

I tried the Simpson website - www.simpsonelectric.com - but I couldn't find it listed. In the paper catalog they call it a "Model 151-2 Line Splitter," part #00544.

I got mine along with the Simpson 150-2 "AC Amp Clamp" by mail order some years ago.

I see you're in Chandler, AZ. I bought some Simpson stuff mail-order from Jensen Tools in Phoenix, not too far away from you. I don't think they carry all the Simpson range, but it might be worth a look.

Re: multimeters best??? #5678 12/02/01 09:42 PM
Joined: Oct 2000
Posts: 3,961
Bill Addiss Offline
Member
Paul,

Actually, mine didn't come with the test leads. This was almost 20 years ago, but it still looks the same.

Bill


Bill
Re: multimeters best??? #5679 12/03/01 09:18 AM
Joined: Nov 2001
Posts: 75
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Bill39 Offline
Member
I've got the same kind of Fluke Meter and it works great, but beware of the continuity function because it is only good to 1K ohm. You may think you have an open circuit but instead the circuit has a big resistor in it.

Re: multimeters best??? #5680 12/07/01 03:37 PM
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pauluk Offline
Member
The continuity "beeper" range on most modern meters is very variable in this respect.

I've seen some which still beep with as much as 2 or 3K resistance, while I have one "el cheapo" brand that quits on anything above about 70 to 80 ohms.

They're fine for checking fuses, identifying switch terminals, etc., but not much use for anything more subtle than that.

Re: multimeters best??? #5681 12/07/01 10:48 PM
A
Anonymous
Unregistered
I see that the Simpson 260 is in use afterall. My professor in my EET program swears by those meters, and I myself have turned to them from time to time. I purchased a Fluke 16 a while ago and have found it to be quite useful both in the lab and out in the field. It comes complete with all the basics (VAC, VDC, IAC, Capacitance, Diode, Resistance, Min/Max, Autoranging, etc.). I have replied heavily upon it while doing trouble shooting work at work. Although I have yet to purchase the jaws for it, I do plan on doing that in the future.

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