Accurate freezer product temps

[mikeref]

I have this situation with a 2 door upright freezer. Client says his infrared readings are showing the temperature of frozen goods are too warm. My readings with digital air thermometer show freezer gets to -20c and cycles on at -17c. I've proven freezer is working fine and tested his infrared against mine, no inaccuracy. Regardless of different nations policies on standards, which method do you use to obtain your medium, air temperature or infrared, knowing the latter only scans surface temps?.. mike.

[taz24]

I have this situation with a 2 door upright freezer. Client says his infrared readings are showing the temperature of frozen goods are too warm. My readings with digital air thermometer show freezer gets to -20c and cycles on at -17c. I've proven freezer is working fine and tested his infrared against mine, no inaccuracy. Regardless of different nations policies on standards, which method do you use to obtain your medium, air temperature or infrared, knowing the latter only scans surface temps?.. mike.


Infared is know to be unreliable for accurate product temp measuring.

If the product is in a cardboard box or plastic wrapping that can throw the readings by quite a few degrees.

In the UK we need to be below -18 C so systems cycle around the -20 mark..

All the best

taz

.

[mikeref]

Infared is know to be unreliable for accurate product temp measuring.

If the product is in a cardboard box or plastic wrapping that can throw the readings by quite a few degrees.

In the UK we need to be below -18 C so systems cycle around the -20 mark..

All the best

taz

.Thanks for your reply Taz24. As the infrared reading measures surface temperature, i am finding the reading changes alot after customers have been hanging on the door even after 20 seconds, or defrost is in progress. Short of jamming the probe of a thermometer into the frozen goods to test temperature accuracy, would there be another way?.... Thinking data-logger over 7 days to read air temperature. Your thoughts appreciated, .. Mike.:)

[coolhibby1875]

the customer sounds like a knob, if the unit is cycling on and off on temperature, and your thermometer is showing correct temp, what more does your customer want? tell him to invest in a proper thermometer and to stop wasting your time :)

[G Cook]

I tried one of the infrared thermometers a while back but soon went back to using digital air thermometer, you know where you stand with them. We get similair calls where there is nothing wrong with the refrigeration, just the thermometer.

We got some basic (but accurate) dial thermometers which we can leave in the customers cabinet to re assure them everything is ok.

[mikeref]

:rolleyes:Thanks to all, seems to me once this "hand gun" was introduced, the shop staff are all over their equipment and now apparent faults are showing up... Mike.

[Magoo]

Infared thermos read the surface temps, which is not proportional to the core temp, or equibulated temp. To be accurate your client needs a spear type temperature probe.
Infa red is a lazy mans tool. Reefer truck companies have similar problem when delivering frozen product to clients, a twit comes out with an IR handheld and says not accepting consignments. Because the IR is reading the shrink wrap temp.., technowledgy gone mad.

[mikeref]

Thanks Magoo. Ran this test with shop management yesterday on a 700 litre freezer with ice buildup inside. Had them scan the ice at its thickest then scraped it away for a second scan of freezer wall. Now they are more confused than ever. I can't let this slide as record keeping seems to be a priority.. Mike.

[taz24]

.

A good old fashioned dial thermomiter is all they need.

Just hang it on the second shelf down so they can see it when they open the door.

They are slow to react so do not show fluctuations, which sounds like what you need.

All the best

taz

.

[taz24]

.

You can't realy blame the staff.

They have a tool to use and expect to trust it.
They just need educating that infared thermomiters are not always the best tool for the job.

taz

.

[Brian_UK]

Not saying this is the answer but they do explain some of the problems with using IR guns in freezers.

http://thermometer.co.uk/521-ir-chill-thermometer.html

Personally I think IR is only for general temperature indicating unless you pay a small fortune for a dedicated piece of test equipment.

Buy a small electronic temperature indicator, Eliwell type, and fit the probe into a product sample for them to watch and record.

[taz24]

.

Infa red is good for taking the temp of ladies bums as they are walking in front of you :D :D :eek:

[Magoo]

Hi Taz24,
for abit of fun get hold of a thermal imaging camera, then you see all the hot spot, sit in the local mall and act like a professional photographer. You will laugh your t*** off.

[FEISTY]

Here in the states the IR guns are the new hot tool to have. We are code required to have a thermometer INSIDE any piece of refrig. equipment. The front outside mounted therm. is a convienence item and only to call attention to a possible problem as you pass the unit. As far as getting an " accurate " reading using the IR type, we mount a " target " spot made of dull finish material and black in color. We put it on the back wall of the unit and hit it with the beam of light. Same place, same material, same quality of reading. I use them once in a while for reefer stuff. It does its job when shooting overhead registers for ac/heat air temp. Also when you can hit a compressor body on that..." WHO THE HELL INSTALLED THAT THING ALL THE WAY BACK THERE !!!! " top of a walk-in job. Other than that, stick with old but honest methods. Late date reply but have been seriously under the weather. Back now so...GO GET THEM !! Have a great day.

[lawrence1]

ahhh magoo,,,you're a sick puppy,but it sounds like fun

[mikeref]

Here in the states the IR guns are the new hot tool to have. We are code required to have a thermometer INSIDE any piece of refrig. equipment. The front outside mounted therm. is a convienence item and only to call attention to a possible problem as you pass the unit. As far as getting an " accurate " reading using the IR type, we mount a " target " spot made of dull finish material and black in color. We put it on the back wall of the unit and hit it with the beam of light. Same place, same material, same quality of reading. I use them once in a while for reefer stuff. It does its job when shooting overhead registers for ac/heat air temp. Also when you can hit a compressor body on that..." WHO THE HELL INSTALLED THAT THING ALL THE WAY BACK THERE !!!! " top of a walk-in job. Other than that, stick with old but honest methods. Late date reply but have been seriously under the weather. Back now so...GO GET THEM !! Have a great day.
Been.. HIC.. having a litt.. HIC.. too much to drink HIC! Feisty?;).

[FEISTY]

I wish it was that type of 80 proof flu. I picked up a fair dose of pneumonia from cold damp rooftops. Forgot the older you get...the tougher you don't. The meds made me feel worse than the illness. Finally gave them up and went back to Dad's old cure all. 2 shots of bourbon and hot tea. Tak the bourbon and stare at the tea !!!!!