RE: Data Acquisition

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Jan Wagner <jwagner-at-cc.hut.fi> 


On Mon, 19 Jan 2004, Tesla list wrote:
 > Original poster: "David Thomson" <dave-at-volantis-dot-org>
 > I'm trying to do true data capture over minutes and hours (maybe days for
 > some experiments).  The parameters I'm looking for are potential, current,
 > resistance, magnetic field, capacitance, inductance and electrostatic
 > potential.  None of my experiments in the near term will be while the coil
 > is operating.  I'm measuring components over time in order to better
 > understand how they react to ambient conditions.
 >
 > I plan to purchase the electrostatic potential meter at
 > http://www.trifield-dot-com/SurfaceDCVoltmeter.htm

$370USD? Ouch! Ebay has a similar but non-digital "electrostatic
voltmeter" (item 2589642299) for a $60 Buy It Now.

If you don't mind tinkering and adding a microcontroller + ADC (and
precision and calibration isn't too important ;) you could
also try a DIY electrometer like
http://www.amasci-dot-com/electrom/sas51p1.html

 > I'm thinking about purchasing the digital multimeter at:
 > http://www.hobbytron-dot-net/product998.html

Did you already see the specs at
  http://www.rpelectronics-dot-com/Data/S-DMR-5200.gif  ?
Max resolution: 10nF, 10mH.
Is this sufficient for your purposes?

 > But the problem with this unit is that it works on the serial port.

For its price, measurement data exchange over serial port is just nice,
for hobby and semi-serious stuff.

You could spend a lot of bucks on GPIB or HPIB enabled equipment and also
get a GPIB card from National Instruments, brilliant connectivity and
easy to program the bus (like, write your own progs). But it's expensive
like h*ll, even on eBay... :-|

 > Also,
 > I'm not sure if I can run more than one instance of the software at a time
 > if I operated 4 units simultaneously.

You can download the software from HungChang and give it a try.
According to google the software appears to be
    http://www.hungchang.co.kr/down/506V203win.zip

I'd think it is possible to select the serial port in the software. If you
run out of COM-ports on the PC you can get add-on PCI cards.

cheers,
  - Jan

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  Helsinki University of Technology
  Dept. of Electrical and Communications Engineering
  http://www.hut.fi/~jwagner/ - jwagner-at-cc.hut.fi