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Glenn Ashmore Glenn Ashmore is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 329
Default Data Logger for Refrigeration

Price is right but I don't like the set 30 minute sample rate, the range or
the 4F accuracy. I (and I think Richard Kollmann) use the Onset Hobo
dataloggers. For $200 including software it has RH, temperature and 2
external inputs. More expensive but you would have about the same amount in
the Lascar units if you want to monitor the same things and a heck of a lot
more flexible. You can monitor interior and exterior temps, humidity and
with about $10 of parts cobble together a hall effect current sensor to
monitor to amps used. Those are the 4 factors you need to monitor
refrigerator efficiency. You can set the sample period anywhere from .5
seconds to several hours,accuracy is about +-1F, or 4 times better and the
battery lasts up to 5 or 6 months.

Support is really good too. Their tech actually designed the current sensor
for me and pointed me to where to get the parts.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"GBM" wrote in message
...
I would like to do some testing on our Refrig unit.

Minimum would be to monitor icebox temperature and voltage to compressor
so
that I can see on-off cycle and resulting temperature vs time for a 1-2
day
period.

If possible, I would like to add current to compressor and temperature in
area where compressor/condenser is located.

Since this is just a fact finding test, I would like to keep the cost
down.

I have seen individual USB temperature and voltage loggers at Lascar
Electronics. For example:

http://makeashorterlink.com/?V2BD2567D and

http://makeashorterlink.com/?P5CD2567D

Does anyone know of a Canadian or US source and especially for a unit that
might accept several inputs?

Someone suggested earlier on rec.boats.cruising that I just use a video
camera, but I need to do this over 24-48 hrs to determine why my refrig
controller at times seems to go into hibernation!

Any ideas welcomed.

GBM