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Products => Test Equipment => Topic started by: Oracle on December 23, 2012, 09:39:37 pm

Title: analog watt meter
Post by: Oracle on December 23, 2012, 09:39:37 pm
hi,

where can i buy an analog lab watt meter? and what's the average price?

specification:
single phase, max 10 A 400V class: 1,5, 1 or 0.5
Title: Re: analog watt meter
Post by: The Electrician on December 27, 2012, 06:58:27 am
What accuracy do you require?  Do you want an electronic meter, or will an electromechanical one do?
Title: Re: analog watt meter
Post by: Oracle on December 27, 2012, 10:54:57 pm
electromechanical possibly.
Title: Re: analog watt meter
Post by: The Electrician on December 28, 2012, 06:22:05 am
A meter such as this:

http://www.ebay.com/itm/Meter-wattmeter-Simpson-model-79-750-watts-10-amps-Max-150-volts-Max-NEW-/150884113846?pt=LH_DefaultDomain_0&hash=item232164ddb6 (http://www.ebay.com/itm/Meter-wattmeter-Simpson-model-79-750-watts-10-amps-Max-150-volts-Max-NEW-/150884113846?pt=LH_DefaultDomain_0&hash=item232164ddb6)

can provide an accuracy of several percent.

These Yokogawa meters are specified as 1/2 percent:

http://www.ebay.com/itm/YEW-Portable-Single-Phase-Wattmeter-Type-2041-10390M-Yokogawa-Tests-OK-/261115411482?pt=LH_DefaultDomain_0&hash=item3ccbb0fc1a (http://www.ebay.com/itm/YEW-Portable-Single-Phase-Wattmeter-Type-2041-10390M-Yokogawa-Tests-OK-/261115411482?pt=LH_DefaultDomain_0&hash=item3ccbb0fc1a)

http://www.ebay.com/itm/YEW-Yokogawa-Portable-Single-Phase-Wattmeter-2041-/150633707952?pt=LH_DefaultDomain_0&hash=item231277f9b0 (http://www.ebay.com/itm/YEW-Yokogawa-Portable-Single-Phase-Wattmeter-2041-/150633707952?pt=LH_DefaultDomain_0&hash=item231277f9b0)

These meters typically don't have a 400 volt rating for the voltage coil, but you can add an additional multiplier resistance to increase the input voltage rating.
Title: Re: analog watt meter
Post by: Oracle on December 28, 2012, 11:05:37 am
ok. thanks. Price is interesting.... Guess something new would be over 250 $.
Title: Re: analog watt meter
Post by: SeanB on December 28, 2012, 02:58:10 pm
If you buy a cheap standard 60A household meter you can make current transformers to increase sensitivity. I did that for myself, using a 10:1 CT to drop the FS range from 60 to 6A, it just reads 10x faster.
Title: Re: analog watt meter
Post by: The Electrician on December 28, 2012, 02:58:55 pm
The Yokogawa meters run about US$650 new.  They're really nice however.  Mirrored scale, taut band suspension, double mumetal sheilding for the movement.

An alternative might be the Gossen Metrawatt Power meter.  I think Dave used one in a review.
Title: Re: analog watt meter
Post by: Oracle on January 03, 2013, 07:25:00 pm
The Yokogawa meters run about US$650 new.  They're really nice however.  Mirrored scale, taut band suspension, double mumetal sheilding for the movement.

An alternative might be the Gossen Metrawatt Power meter.  I think Dave used one in a review.

yes, they are nice, but if a new meter runs about $650 which is the equivalent of 500 euros, probably i would take an electronic one which has better performance, and it's computer controlled so you can use some monitoring/measure software.

I don't know Grossen Metrawatt instruments: never used and heard about them. I only used a Hameg HM8115-2.
Title: Re: analog watt meter
Post by: Oracle on January 03, 2013, 07:27:32 pm
If you buy a cheap standard 60A household meter you can make current transformers to increase sensitivity. I did that for myself, using a 10:1 CT to drop the FS range from 60 to 6A, it just reads 10x faster.

 but where i get a household meter + the ferrite core for the transformer?
Title: Re: analog watt meter
Post by: SeanB on January 03, 2013, 07:47:19 pm
Electrical wholesalers or other electrical suppliers for the meter. The core is not a ferrite but a wound core from a small toroidal transformer, or you can use any small mains transformer and remove the windings with a knife and use the core and the bobbin. You are winding 2 simple windings, one of a single turn of 10mm wire as the secondary and a 10 turn one of 2.5mm wire as primary.
Title: Re: analog watt meter
Post by: Oracle on January 03, 2013, 09:27:04 pm
Electrical wholesalers or other electrical suppliers for the meter. The core is not a ferrite but a wound core from a small toroidal transformer, or you can use any small mains transformer and remove the windings with a knife and use the core and the bobbin. You are winding 2 simple windings, one of a single turn of 10mm wire as the secondary and a 10 turn one of 2.5mm wire as primary.

 it's interesting... but what household meter should i have, an old electromechanical one or a digital one?
Title: Re: analog watt meter
Post by: SeanB on January 04, 2013, 04:47:43 am
Any one will do, depending on what you want to do. They both have advantages and disadvantages for measuring.
Title: Re: analog watt meter
Post by: Oracle on January 04, 2013, 07:55:22 am
Any one will do, depending on what you want to do. They both have advantages and disadvantages for measuring.

of course same for multimeter.

I'm looking for something like this?

http://www.ebay.it/itm/contatore-elettrico-di-energia-tipo-enel-220-volt-/170429311183?pt=Attrezzature_e_strumentazione&hash=item27ae60e8cf (http://www.ebay.it/itm/contatore-elettrico-di-energia-tipo-enel-220-volt-/170429311183?pt=Attrezzature_e_strumentazione&hash=item27ae60e8cf)

Because the electronic one it's very expansive than this one. 
Title: Re: analog watt meter
Post by: Oracle on January 04, 2013, 08:05:11 am
I would like to share this, speaking about analog instrument/meter ecc ecc :

http://www.ganzinst.hu/products/portables/port_selector.htm (http://www.ganzinst.hu/products/portables/port_selector.htm)

all instruments are class 0.5 or 1.

Don't know the price list....