Procedure for calibrating temps.

[chew*]

I was wondering if anyone had a procedure for calibrating correct temps with an Aquacontroller. I have conflicting results between 2 digital devices and need to find out which is correct. Namely the temps vary to 1.5 degrees between my pinpoint wireless thermometer and my AC jr.

Pinpoint reads 81.6 and AC jr reads 83.2 which also causes the dillema of have my temps been to high as of late.

I know from when i was overclocking computers we used to get a cup of icewater which should display a certain temp to tell the accuracy of DMM's with temp probes. Not sure if the range on this allows for 0 C though.

 

[chew*]

Looks like no one has covered or tried to verify correct temps. I will work on this more, my mother in law works at a hospital, if anyone has accurate measuring equipment I'd have to say it would be them.

 

[chew*]

Looks like I found a candidate. I can live with +/- .2f

http://www.dcglass.com/htm/p-thermnist.htm

210-620-C

 

[customclimates]

Brian,
I used three cheep refrigeration thermometers. All read pretty much the same temperatures. I put one in my display, & two in my sump. After 24hours of acclimation I felt I had a pretty accurate guideline
http://www.arizonatools.com/tools/digital-and-dial-thermometers/detail/ROB50597/

 

[xp964]

I was curious so I looked on their homepages. Neptune Systems says that the accuracy of the Aquacontroller Jr is +/- 0.3 F. American Marine (Pinpoint) didn't list an accuracy at all, not even in the manual, which automatically make me suspicious. I'd go by the Aquacontroller.

If you you want to test calibration, standard procedure for thermometers is to make an ice slurry. Mix 50/50 crushed ice and water, stir vigorously, and the bath will read about as close to 0C/32F as you can get. Don't use salt water though.

You might want to check with the manufacturer and see if they make a calibration key. Some thermometers, usually ones with a non-fixed probe, can accept a simulator input. The simulator "tells" the thermometer that the temp is 32F, and if doesn't read 32 F exactly on the display, the unit needs calibration. It's usually cheaper to buy a new thermometer than have it calibrated, though.

 

[MikeG]

I did the ice water and used an average of 3 different thermometers that we have. Seemed to work good.

 

[chew*]

Yah thats the way we used to test the calibration of our flukes when I was into freezing computers. I will try the ice bath method tonight, just not sure if these digital ones range that far.

 

[chew*]

Custom, have you had any experience with using sporlan controllers? Being that its far from cheap and utilizes a temp probe I was wondering on the accuracy of it as I still have mine.

 

[MikeG]

Yah thats the way we used to test the calibration of our flukes when I was into freezing computers. I will try the ice bath method tonight, just not sure if these digital ones range that far.

I calibrated kitchen thermometers in ice water and then checked my tank water with those and looked to see the difference between my temp probe and the thermometers. They read the same. Not sure why I didn't even think to just put the temp probe in the ice?

 

[chew*]

Ok so after sitting in a ice bath for about 5 minutes the pinpoint hovered at 31.6 then dropped to 30.7 and settled so its off by 1.3F which most probes are usually +/- 1F

Sporlan temp controller is reading 32f which as much money as it cost it should.

The aquacontroller appears to be stuck between42.4-42.3F which I'm guessing is its lowest capable reading......

At this point in time I'm going to have to say that my sporlan is far more accurate and I will use that to calibrate the aquacontroller.

Testing in tankwater appears that the pinpoint is more accurate then the aquacontroller at its intended temperature range when compared with the sporlan, both reading 80f while the aquacontroller is hovering at 82f

I turned the heater on untill the sporlan just registered 81F then set the aquacontroller to that. It was off by 1.2f, after scanning through manual I found this info.

"Also the AquaController Jr can control both a heater and chiller to maintain a stable temperature environment in the tank. The heater and/or chiller enable and disable temperatures can be set independently. Given the tank has an adequate heater and chiller, the temperature can be maintained within +-.3 °F."

I found nothing that stated accuracy save for the fact it has been pre calibrated at the factory..........

 

[Jim Tansey]

Keep in mind you are only calibrating at one point, far away from our point of interest, even if you set that point you have done nothing to adjust the slope.

Jim

 

[customclimates]

My ACJr was off 7 or 8 degree's when I first purchased it. Could not believe that for the money you spend on one. I called Neptune & they said basically just to offset it in the temperature set up….Go figure!

 

[chew*]

Thats the way i felt custom, I said nah no way its wrong for for $300 but then last night I saw my temps rising, looked and my heater was on ( it's not on the aquacontroller yet ) My heaters set to come on at 78 and the controller was saying 79+ which led me to believe it was way off.

Jim as far as calibrating it I have alot of faith in my Sporlan chill controllers temp probe, the unit cost well over $300 , Its a professional grade HVAC device designed to turn a heating/refrigeration device off and on based on temps. In short form Its a very very expensive thermostat with a range from -50f to +127f

Also Ice baths are a very effective means of calibrating temps

At least i found a use for an old toy of mine custom, Now i just have to let you look at the unit and see if we can convert it to a usable chiller for a reeftank as the big copper coil is probably not suitable...........

 

[Aquaman_68]

Wow...This thread is crazy!!! I use an octopus 3000 & I never had that kind of difference in the actual temp. (when compared to various sources) (I have a lab grade probe....Don't know if that matters or not!!)

 

[chew*]

hmmm thats why the octopus is more money

 

[Jim Tansey]

Ice bath is an effective means for 32F (0 C), but one point does not make a curve.

Jim

 

[Aquaman_68]

TOO MANY GADGETS TO FAIL...... The meaning is..... I'm worried that gadgets will fail

If any of you are in to redundant sources & your using a controller to run a chiller, heater, or both thru x-10 or other means LQQK......


You can also get a Rancho controller & put it in a series after the switching cable pre chiller & heater. This will work as a back up if your probe goes wacky on your controller. You will have a secondary source to shut off & turn on the equipment if the first in line fails... (I would suggest using the controller feed first & then thru Rancho controller second!!)

 

[chew*]

Thats basically how i have mine setup aside from the fact that i'm using the supplied controller that came with the heater into the aquacontroller, if the finnex controller goes wacky( they have been known to ) the aquacontroller will shut it down. But we've already talked and you know im a big redundancy buff and a firm believer in murphy's law. I may incorporate my sporlan controller later on down the line as its far superior quality than the finnex.

FYI the reason accurate temps are such a concern to me on the aquacontroller is due to ATC that is integrated into the programming, as custom climates said his was off by 7F, that would also throw off accurate ph measurements which would in turn throw off other chemistry like setting a calc reactor to shut off if ph shifts.............

 

[Aquaman_68]

Thats basically how i have mine setup aside from the fact that i'm using the supplied controller that came with the heater into the aquacontroller, if the finnex controller goes wacky( they have been known to ) the aquacontroller will shut it down. But we've already talked and you know im a big redundancy buff and a firm believer in murphy's law. I may incorporate my sporlan controller later on down the line as its far superior quality than the finnex.

FYI the reason accurate temps are such a concern to me on the aquacontroller is due to ATC that is integrated into the programming, as custom climates said his was off by 7F, that would also throw off accurate ph measurements which would in turn throw off other chemistry like setting a calc reactor to shut off if ph shifts.............

Kalk reactor should be set up on a seperate controller & probe from the main controller. This way if probes are off you have failsafes!!
Ya know I'm a mechanic by trade.....But that wasn't how I got so OCD about redundancy....It was from Open Water Diving!!! Just the same.....Mechanics know "mechanics" (& they know that anything mechanical is going to break at some point!!!) They just don't have a crystal ball!!

 

[Greg Hiller]

IMO you are really more interested in an accurate reading around 80 F, not 32 F. I've always just gone to a local shop, glanced at some of the glass thermometers on the rack and taken home one that seems the average of them. In most cases there is very little difference between them. You can of course purchase a calibrated thermometer, but they tend to be pretty expensive.