Multimeter help

[ian-d1]

I all, just joined up and naturally have a question, but hi first

I have purchased a "cheap" multimeter today as I need to trace a drain on my car battery. The problem is that I need to test the amps constantly over a 20 minute period and unfortunately the unit I have says UNFUSED and MAX 10 SEC EACH 15 MIN which I persume is why after about 10 seconds the unit stops reading the amps.

Is there a method of getting around this, such as placing a fuse between the connection; or would a FUSED multimeter be a better option as I can always take this one back. I presume it is possible to monitor amps over that length of time (the amps will be around 2.5 max) with a multimeter, just like you can voltage.

 

[ian-d1]

Anyone have an idea? Was hoping you guys would be in the know. Went to buy a FUSED on today and even most of them (within a reasonable price range) state MAX 10 SECS which isn't great for what I need to do!

 

[telectrix]

well, you can't use a clamp meter, as it won't work on dc. what yo need is an old fashioned dashboard ammeter as used to be fitted to cars prior to 1970ish. you can still buy then at motor accessory shops. they read around 30-0-30, just fit in line with your battery feed. not very accurate though.

 

[MarkieSparkie]

Hi Ian, welcome along to the oasis in the desert of electrical confusion.
Unfortunately you have found that with tools in general and test gear in particular you get what you pay for. On this site we tend to drone on and on about buying the best quality gear, because from our collective experience we know its an investment which is far less likely to let you down in the critical moments, and if the worse happens its usually repairable unlike the cheap end throw away stuff.
Your best bet would be to return your original purchase and get your money back. Then look at meter aimed particularly at the car repair market, because your requirement is more likely to be a standard feature even at the DIY end. At the DIY end "Gunson" is a well respected make, spanning the DIY/middle ground are "Draper" and "Machine Mart" and aimed at the professional there are "Sykes-Pickavant", "Sealey", "Laser Tools", "Snap-on" and "Mac"

 

[ian-d1]

Thanks for the replies. I went back to the shop today to look at alternatives, but even the more expensive ones which were FUSED state maximum 10A for 30 seconds, or 60 seconds. I need to be able to leave the meter reading the amperage of a particular fuse terminal for at least 20 minutes. The terminal on a 10 second test with the current meter shows 2.5amps, but I need to know what it drops to when the car goes into sleep mode, as applying the meter to the terminal is merely offering up the amperate whilst the satnav/tv etc boots up. Will a FUSED one, even with a 30 second limit work?

Is it correct that my UNFUSED meter would only read for 10 seconds before automatically dropping to 0amps, as I tested with a glovebox light and it reduced to zero, yet the light remained on; maybe the meter I have has some kind of safely cut off? Does that sound about right!

 

[MarkieSparkie]

Ian, I have found a Gunson Testune multimeter in good working order, which I no longer need (£20 to you including p&p), this meter has continuously rated 10A range. Sent me a personal message on here if your interested.