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Which Fluke?

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  • #16
    You might consider a current meter (with probes AND clamp) if that is what you are missing. Aside from the hassle of changing the probes over I find when doing current measurement with my multimeter I usually end up using a second meter to measure voltage somewhere at the same time. For example, when checking bias I like to see what the plate voltage does. When checking AC draw, I also want to monitor the voltage from the wall or variac. With the clamp, you can hook around the AC hot in the chassis and not have to break into the circuit. Or you can dedicate an extension cord with outer insulation peeled back and hook around the hot to measure current draw. Sounds like the clamp might also be useful for some of the other AC stuff you are dealing with.
    With a dedicated current meter there is much less chance of frying something if you forget to change the probes back over to measure voltage.
    Like you, I wanted one meter that did everything, voltage, current, freq., cap., inductance, and diode. In retrospect I would get a second meter for current. And, like Enzo mentioned, since the demise of tape machines I don't really need the frequency counter anymore.
    One thing to keep an eye on with multimeters is the "burden voltage" spec. for current measurement. I spent a couple hundred on my meter and later realized when measuring in mA range the burden voltage is 10mV per mA. This means in mA range I have 10 ohms between the probes rather than a short. If, for example, I am measuring 200mA through a 15V regulator the circuit will only get 13V to it and likely not work right. Also I can't use shunt method for biasing with any kind of accuracy because the resistance of my "shunt" is too high. You don't want a meter with a burden voltage of more than 1mV per mA, good meters probably more like .1mV per mA. With Fluke this shouldn't be a problem.
    I think your scopemeter and a good current meter/clamp would be a great combination.
    Originally posted by Enzo
    I have a sign in my shop that says, "Never think up reasons not to check something."


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    • #17
      Originally posted by g-one View Post
      You might consider a current meter (with probes AND clamp) if that is what you are missing. Aside from the hassle of changing the probes over I find when doing current measurement with my multimeter I usually end up using a second meter to measure voltage somewhere at the same time. For example, when checking bias I like to see what the plate voltage does. When checking AC draw, I also want to monitor the voltage from the wall or variac. With the clamp, you can hook around the AC hot in the chassis and not have to break into the circuit. Or you can dedicate an extension cord with outer insulation peeled back and hook around the hot to measure current draw. Sounds like the clamp might also be useful for some of the other AC stuff you are dealing with.
      With a dedicated current meter there is much less chance of frying something if you forget to change the probes back over to measure voltage.
      Like you, I wanted one meter that did everything, voltage, current, freq., cap., inductance, and diode. In retrospect I would get a second meter for current. And, like Enzo mentioned, since the demise of tape machines I don't really need the frequency counter anymore.
      One thing to keep an eye on with multimeters is the "burden voltage" spec. for current measurement. I spent a couple hundred on my meter and later realized when measuring in mA range the burden voltage is 10mV per mA. This means in mA range I have 10 ohms between the probes rather than a short. If, for example, I am measuring 200mA through a 15V regulator the circuit will only get 13V to it and likely not work right. Also I can't use shunt method for biasing with any kind of accuracy because the resistance of my "shunt" is too high. You don't want a meter with a burden voltage of more than 1mV per mA, good meters probably more like .1mV per mA. With Fluke this shouldn't be a problem.
      I think your scopemeter and a good current meter/clamp would be a great combination.
      Thanks a lot G-one.

      Well, sugestion noted. I'll keep this in mind. For the moment, exept if i find a 179/79 dead cheap. I looking at 87's. It will be secondhand thought. Can't afford a new one for the moment. The scopemeter is nice, but it's batteries are crap, normal AA/LR6 go in there, and if it's cold, i don't have more than 1/2 hour work ahead of me. I'll most certainly take a cheapo amperage clamp. Thanks a lot for the sugestion.

      Bye.

      MAx.

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      • #18
        Have you tried lithium batteries for the cold? We have a wireless thermometer, the sensor/transmitter outside wouldn't work right below about -10C. With lithium AA's no problem down to -30C for a few years now without replacement.
        Originally posted by Enzo
        I have a sign in my shop that says, "Never think up reasons not to check something."


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        • #19
          Hey guys!

          Finaly got this one!

          Fluke 87V Digital Multimeter , in Great Condition. en vente sur eBay.fr (fin le 07-févr.-11 14:58:07 Paris)

          Not the cheapest, but good enough a price imho. 141.5 euros shipped.

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