IR Thermometers?

[flyingcow]

Not a new thread by any means, but I would like to use one to do a quick check of my tanks of milk. I haul from dairy farms to plant. One part of my job is to check tank temps before i accept the milk on my truck. I have a probe type of thermometer that is all calibrated, but i want to use a IR for a quick scan. Temps will range from 32f to 45f on normal ttemps. I don't usually load anything above 42f. Don't want to spend much $$$'s, as it can be a rough use. Not uncommon to drop things, wet environment, etc. Thinking about having it on a string around my neck, not a good thing to drop stuff in the tanks. we won't go there...

 

[Realstone]

I got a cheap one ($40 - Canadian Tire). Works ok for giving me stove top and flue temps and other things. But whatever one you get, I suggest you calibrate it against items of known temperature on a regular basis if you are going to using it for something as important as you are. Mine reads about 2° high.

 

[Backwoods Savage]

Sounds like a good idea to me. First thing I'd do would be to check a few times the IR vs the probe. I'm betting it will be close. Naturally you'll churn it a bit before testing? Ah, I remember those days after the milkman left came the tank cleaning... But it really did not take that long.

 

[MasterMech]

Would you be checking the liquid inside the tanks or just the surface of the tank? One thing you should know about IR thermometers is that different surfaces at the same temperature will give different readings. This is because the different surfaces have different levels of emissivity. Polished stainless surfaces are known to throw off an IR thermo. In no way am I discouraging you from getting one of these little temp guns but heed the advice to check the readings against your calibrated probe. You may need a model with adjustable emissivity controls (haven't seen that on anything "affordable") or you will have to do the offset in your head. Might be worth making a couple phone calls to the companies that make these things and asking them what they think of your intended application.

 

[Ashful]

Good advice, MasterMech, or you can just always shoot against an object of the same emissivity. If you're shooting the outside surface of your tanks, and they're all painted the same, then you may already be i good shape. I spend my share of time behind an IR camera, and something as simple as Scotch Blue Painter's Tape applied to the surface being "shot" can help to bring a wide range of different surfaces to the same emissivity.

 

[Dairyman]

I have one from harbor freight and like it. MM is right about the emissivity throwing these things off. Just for fun I just checked the milk in the tank and it read 41° and the tank thermostat was at 39°. Note I didn't run the agitator. If your just wanting one for some fun get a cheepy. If you really want one to use then you'll need a food grade and there $$$.

 

[MasterMech]

Good advice, MasterMech, or you can just always shoot against an object of the same emissivity. If you're shooting the outside surface of your tanks, and they're all painted the same, then you may already be i good shape. I spend my share of time behind an IR camera, and something as simple as Scotch Blue Painter's Tape applied to the surface being "shot" can help to bring a wide range of different surfaces to the same emissivity.

Forgot about the tape trick.

Guess I'm used to shooting surfaces way too hot to try taping them...

 

[flyingcow]

I will be shooting the surface of the milk, before and after agitation. I expect a degree, maybe 2 at most difference between my "official" thermometer and the IR. No biggie.

Dairyman- I've noticed a a couple of degrees diff before and after agitation. As you know, usually the temp probe for the tank is in the bottom section of tank. If the tanks don't auto mix the milk so often, the milk on top will separate and warm up. The older tanks don't have the agitator set up to come on every so often. Very noticeable diff in temp in the shoulder season. The windows are open, screen doors are in, the milk room stays at outside air temp. In the 30/40's? Usually the tank doesn't call for cooling until milk gets to about 40f. The milk sits there with no agitation for several hours. Separates, warms a little on top, etc. Not uncommon to have elevated PI's. All my milk goes into a table top milk processing plant. Those plants are pushing shelf life, and PI's at farms are top on there list of standards. I have had a few unofficial tests done from the same tank. Skimmed the top before agitation, took one 5 minutes into stirring, and the 3rd after 10 minutes. 2nd and 3rd on the egde of being too high. 1st was off the charts high. And this farm has impeccable quality. Just every so often would spike a high PI once in a while.


Back to my IR. It's a 3 to 4 minute process to use my official probe type. I have 18 farms I pick up every day. Got to sanitize it, etc. Plan on using a IR on all tanks every day. Us milk haulers get pretty good at judging milk temps when we smell the tank. But in the hot humid times, milk at 50 can fool you. It's 90f in a milk room, open top, stick your nose down into the tank, anything feels cooler than 90f on a hot humid day. Also, about half my tanks have a working thermometer on the them, but the other half I calibrate once a month with my "official" probe, and record.

I plan on buying a cheap unit and see how it works.

 

[Backwoods Savage]

Hey flyingcow, thank God you aren't picking up that milk in cans yet!

 

[flyingcow]

Hey flyingcow, thank God you aren't picking up that milk in cans yet!

The Amish are doing just that, but dumping their cans into a modern tank. Usually 4 family farms per community tank room. I can back in and give them a good rate on picking up their milk. They have very good quality milk.

 

[firefighterjake]

The Amish are doing just that, but dumping their cans into a modern tank. Usually 4 family farms per community tank room. I can back in and give them a good rate on picking up their milk. They have very good quality milk.

In Smyrna/Smyrna Mills or somewhere else . . . actually if memory serves me right there were a few families in the Fort Fairfield or Presque Isle area as well.

 

[flyingcow]

In Smyrna/Smyrna Mills or somewhere else . . . actually if memory serves me right there were a few families in the Fort Fairfield or Presque Isle area as well.

I've got 3 community milk rooms. one in Fort, one in easton, and one in sherman. With many more to follow. All 3 are of the same "tribe", if you will. They are not with the groups in Smyrna. These guys are old school Amish. Steel wheels, milk by hand, etc. The community milk rooms will serve up to 4 families. Each family has it's own tank.

 

[golfandwoodnut]

For a cheap but pretty reliable device you cannot beat the Harbor Freight one that you can pick up for $20 some dollars. You could consider it a throw away if you are not happy with it. We have a lot of fun around the house with it, the kids test everything.

 

[flyingcow]

For a cheap but pretty reliable device you cannot beat the Harbor Freight one that you can pick up for $20 some dollars. You could consider it a throw away if you are not happy with it. We have a lot of fun around the house with it, the kids test everything.

Thats what i'll do. thanks.

 

[DanCorcoran]

Thats what i'll do. thanks.

I have one and it seems reliable and accurate. I've found that when it starts giving inaccurate readings, it's just time to change the batteries. If you buy them locally, they're very expensive, but if bought online they are very inexpensive, even when shipping is included (I got this tip from others on this forum).

 

[flyingcow]

I have one and it seems reliable and accurate. I've found that when it starts giving inaccurate readings, it's just time to change the batteries. If you buy them locally, they're very expensive, but if bought online they are very inexpensive, even when shipping is included (I got this tip from others on this forum).

Thanks. I ordered my moisture meter online. Much cheaper. I will do the same.

 

[MasterMech]

Thats what i'll do. thanks.

http://www.tooltopia.com/mastercool-52224a-sp.aspx

Check this one out flyingcow. 12:1 spot ratio (vs 8:1) and the price is awesome for one with that spec sheet.