For you Texans, no I'm not talking about ponds. LOL

Looking for some decent quality digital temp displays with probes for small DIY RAS tanks. Something I can mount to the tank for easy reading. Tried a couple cheapies that are used for aquariums off of Amazon last year. Went into the trash can in no time. Didn't even read the same temps!

This one seems better quality and higher priced from Granger. Probe is waterproof.


http://www.grainger.com/product/EXTECH-Digital-Thermometer-4FB69?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/4FB69_AS01?$smthumb$

I have a high quality YSI 550-A D.O/temp meter hat does a good job of measuring temps, but it would be nice to not have to lug it around and just look at a display on the tank.

Wonder if you could find one that is wifi capable. Would be handy if you could monitor temps on your smart phone while your away. (Like my home HVAC thermostat has an iPhone app)

Don't even have a cell phone! LOL
I think I'm the last person on earth without one!

Again, I envy ya. I got a smart phone that is just plain stupid. Don't know if it would suit your purpose but I just have an old fashioned thermometer that is in a plastic body that I have screwed to a 4' broom handle and just clamp that on the end of the pier. Couple of bucks at the dollar store and surprisingly accurate. Have ta scrub the algae off every few weeks.

You know Bob that's an idea. If I get a big enough one and it's water proof it just might do it. You're giving me ideas!

Well Cecil anything I can do to help get those Tilapia ready.

If you want to check accuracy, do an Ice Point Melt Test.

Fill a glass full of ice, pour in some water to the top, let the ice melt a bit, stick the thermocouple, or whatever in there, swirl it around a bit and that should give you your offset from 32°F, or 0°C.

I have a bunch of NIST Certified stuff here, but people don't understand what this really is All this is, is NIST is telling you how screwed up your stuff is and the offsets you need to deal with.

FWIW the food industry might provide an option for you. Digital thermometers are typically either thermistor or thermocouple and remote probes allow reading outside the environment being checked. Just walk up to the tank and press a button for an instant reading or, leave it on, and it can sound an alarm if a temperature is exceeded. A good one is less than $50 and accuracy is really quite good.

Find me one for under $50.00 that would stand up. I know a huge blueberry farm and processing center that would love cheap stuff.

Any communication protocol to get back to a master?

Usually ain't cheap to rig something like this up.

Here is a cheap but good one of the type that I had in mind. I may be missing something though as the statement "that will hold up" makes me think the duty/environment is much harder than I am thinking.

http://www.amazon.com/MT004-Kitchen-Ther...TZ0CMD7W3DS1A9G

Way off dude. You said the food industry and not someones kitchen at home. Two very different worlds.

Sorry for the confusion. Matter of semantics. I consider restaurants part of the food industry and these type devices are used routinely to both cook and monitor food temps in that venu.

Understandable.

Going over the blueberry rig again today, the last price from a few years ago to monitor temp and humidity in 12 storage rooms was $28K. Oh, they did not want to spend that much.

If simple and cheap are the consideration then a floating thermometer might work.
I have been using a floating brewing thermometer in my aquarium for years.
They are extra large, maybe 8" long, easy to read, not like the little ones sold in pet stores.
It is glass, so you need to be careful and I only use one because it was laying around, haven't made beer in 15 years or so.
They range from $10-20, not sure of the accuracy of them, would have to check them to be sure.

Just a thought.

Cecil,

Here is the one I am trying.

http://www.amazon.com/HDE-Digital-Fish-A...QFRM3F9K41DKYNQ

I'll let you know how it does.

Good luck Brian. Threw two of those in the trash can last year. LOL

I know this may be way out of your $ range, but have this one for keeping an eye on the 75R compressor temps: CUB 5
Have the RS-485 (Modbus) and relay option with a bolt on thermocouple from Omega Engineering. It was left over from a project and had it deducted from my paycheck. It's actually the least expensive gizmo I have, but thought it would work perfect for this application.

Per I/O point, it's quite expensive tho, but really cute!

Quite a temp range!

FWIW for a thermometer that is the most reliable and inexpensive, I would go with the old mercury or a bimetallic dial.

Think I''ll give one of these a shot:

http://www.amazon.com/Extech-401014-Indo...rmometers+large

Can measure air temp and water temp at the same time.

That could/should work. Is the outside probe rated to be submerged in water if that happens?

I have a few Extech meters and they have been pretty decent.

Except...

...Had a decent multimeter with temp and all that jazz on it. A customer borrowed it while at my shop to check voltage at a 3 phase outlet. He had it on the wrong settings checking 480VAC and that sucker blew up right in his hands Should have just blown the internal fuse, but this thing blew up! There was no fuse holder left at all. Complete melt down inside. Did the company offer to replace it? NO!!!

Bought another one and that drowned in a bin during a water leak. Tried to dry it out, but it was too late. Battery was connected long enough under water to smoke the thing. Never bought another one.

I have a bunch of type K and type J thermocouples, as well as a few PT RTD's. A number of them have the traceable calibration tags, which makes it easier to set your offsets.

These gizmos are pretty sweet for remote I/O: 4018+ I noticed the price dropped $75.00, not too long after I bought one. Oh well.

Another really sweet input module is this: 1762sc-IF8u Super easy to set up and is very robust for many years of trouble free operation.

Yeah, I know. I've spent way too much on unnecessary gizmos, but it's a damn addiction!

Cecil - I started monitoring the temperature of my creek as a prelude to building ponds. I just picked up a swimming pool thermometer. So far it meets two of your criterion - it is rugged and inexpensive. I don't know if you need great accuracy or just good repeatability. I imagine you could find one with larger numbers. (Though not as large as your digital display.)

It might be a cheap enough option to have a dedicated thermometer in each tank. I don't know if you ever have any transferrance or contamination problems in your ventures.

Thanks!