IR Temperature gun?

BDofMSP · Oct 31, 2013

Hi,

I've never owned an IR temperature sensor gun. After following threads here for a couple months, it seems like a great tool for me to have onboard. Does anyone have insights on brands or features that I should be looking for? I've seen models that range from $20 to $200 so I'm wondering what makes one "good".

Thanks,
BD

Bilgewater · Oct 31, 2013

I bought one from Harbor Freight. Works just fine. It is currently on sale for about $38.00.

Edelweiss · Oct 31, 2013

It's actually a good buy. I just bought one to leave on the boat, not expecting much, and I tested it against a Fluke IR Therm. (around $1000 instrument) at work. Within the Temp ranges we're talking about , 30 - 500 F it had < 2% error, which is pretty good for a non contact sensor.

Shoalwaters · Oct 31, 2013

Got mine from Harbor Freight too ($29.99 in Jan 2009). Still going strong. I use it for checking a/c outlet temps. Squirt it at the exhaust mixing elbows when I want to do some worrying.

fryedaze · Oct 31, 2013

The best advice I can give about an IR temp gun is don't point it at a womans forehead when she states she is having a hot flash. It ends badly. "Don't ask me how I know" :facepalm:

Steve · Oct 31, 2013

I bought a Craftsman kit several years ago it included multimeter, Ir Gun and Amp clamp. Maybe 60-70 bucks. All works well.

gwkiwi · Oct 31, 2013

I use mine all the time it is one of three things I always take down to the engine room during underway engine checks and wonder how I have lived so long without it.

At dock today I shot my 8D batteries to check their temp to confirm the battery charger was correctly calibrated to the battery temp range.

Only cavet is be careful when putting it back in its case for storage as it is easy to compress the trigger and run the battery down.

Mine came from Amazon and like I said wouldnt leave the dock without it best value for money in a long time.

Bay Pelican · Oct 31, 2013

Key elements for which to get "normal" temperature reads are:

Batteries
exhaust elbows
pre and post thermostat fresh water (coolant) hoses
coolant reservoirs

You will find that if you have the normal temperature readings on these items that troubleshooting problems will be easier.

I am sure there are many more items to take readings on.

Marty

BDofMSP · Oct 31, 2013

Thanks for all the replies. I will definitely be taking baselines. I trailer my boat so I think I'll also use it to check the temp on the hubs and brakes on the trailer.

It's probably the first time ever that something I need for the boat doesn't have to be "the most expensive one possible"

We're already buttoned up for the winter here, so this tool will be going on my Xmas list!

BD

captrigney · Oct 31, 2013

For 30 bucks it doesn't make sense NOT to have one. Here is a guide from Marine Engine Analysis

If you have not used a laser temperature gauge before you’ll be amazed at how much information this simple tool will show us about our engine. (See Tradeaboat April for full use instructions)

Begin by scanning the gearbox looking for hot spots. Pay careful attention to the area of the case around the clutch packs, and the gearbox output bearing. If any part of the gearbox is going to build up heat it will be during this bollard pull test. The complete gearbox should be under 80C, and 60C is typical.

Continue checking with the laser gauge along the cylinder head. It should show about 75-85C everywhere. There should be no hot spots. A hot spot would be more than a five degree C change in the head from one end to the other.

Note-Testing the area directly around the exhaust manifold does not count as a “hot spot”, as this will be hot due to the high temperature of the exhaust.

Check the oil temperature by shooting the oil filter or oil pan. The oil temp should be about 7-10C above the head temperature and not above 95C.

Check the inlet to the salt-water pump and outlet of the final heat exchanger. With most engines the temperature difference should be less than 10C. A higher temperature difference can indicate an engine producing too much heat (IE failing head gasket) or too little water flow (IE clogged salt water system).

Check the fresh water temperature inlet and outlet of the heat exchanger. The difference should be about 10C and stable. You should be able to move the laser along the body of the heat exchanger and show the cooling effect of the heat exchanger. By this method you can see how much reserve cooling you have left in the heat exchanger.

The pre turbo exhaust temperature should be about 300-450C. After turbo it should be a bit lower. Check the exhaust gas temp between the cylinders and exhaust manifold for each cylinder. Normal for a loaded non-turbo engine should be 300C. A cylinder temp lower than the rest shows a clogged injector or maybe a dead cylinder. A high cylinder temp possibly shows a leaking exhaust valve, or poor injector spray pattern.

MC Escher · Oct 31, 2013

I have a Raytek MT that I think I paid $80-90 bucks for when I was at Xerox and it STILL works great after 13 or 14 years. I think it's been running on the same 9 volt batter since 2007.

The current version, a Raytek MT4 Mini Temp Non-Contact Thermometer Gun with Laser Sighting is going for about half that price on Amazon. ($46)
It has a temperature range: 0 to 750 Degrees F (-18 to 400 Degrees C), so you may want a wee bit more range; but there are plenty of options with wider range and many for less money.

Here are some examples, filters down to just the dozen with the highest user ratings:

IR Thermometers on Amazon

Anthonyd · Oct 31, 2013

BDofMSP said:
Hi,

I've never owned an IR temperature sensor gun. After following threads here for a couple months, it seems like a great tool for me to have onboard. Does anyone have insights on brands or features that I should be looking for? I've seen models that range from $20 to $200 so I'm wondering what makes one "good".

Thanks,
BD

As has been stated, there are many brands that offer a good unit. Look for the percent of error, the type of optic that is used, the field of view, and the range. Some units are only accurate if you are within two or three inches. This may be difficult sometimes. The better unites will adjust for ambient temperature from as far away as 16 inches or more. Most will read in degrees F and C, I prefer C, and come with a one year warranty. Maybe try to find out where you will be shooting the target from the farthest, and find the one that works well at that range.

healhustler · Oct 31, 2013

fryedaze said:
The best advice I can give about an IR temp gun is don't point it at a womans forehead when she states she is having a hot flash. It ends badly. "Don't ask me how I know"

I had one till I did exactly what Fryedaze did. (SMACK). Hasn't worked since. :blush:

tpbrady · Nov 1, 2013

Costco has a temp gauge and moisture meter in a single blister pack for under $40. Both seem to work pretty well.

Tom

markpierce · Nov 1, 2013

I have one. It is fun to occasionally check the temperatures of the cement docks, the interior of the boat, and the relative temperatures of the boat's various color.

jleonard · Nov 1, 2013

I also have a Raytek, with a laser dot, it's probably 15 years old and still works well. Back then it cost about $90 and it was one of the few available at the time.
It has more than paid for itself both on the boat and at home.
If I were to buy another I'd probably get a low cost one as they all seem to work well.

WillieJ · Nov 1, 2013

jleonard said:
I also have a Raytek, with a laser dot, it's probably 15 years old and still works well. Back then it cost about $90 and it was one of the few available at the time.
It has more than paid for itself both on the boat and at home.
If I were to buy another I'd probably get a low cost one as they all seem to work well.

+1 on the Raytek. The company is owned by Fluke. The MT-6 is available on Amazon for about $60. It is switchable F C. Also see Infrared Thermometer | IR thermometer | Non Contact Temperature Sensors for specs and info.

C lectric · Nov 1, 2013

Pick several spots on the engine and gearbox. Paint the spots with flat black paint. These tools read best, most accurately from dark flat surfaces. About 1" - 1.5" diam.
Use these spots for repeatability. Two mistakes people make is to shoot all over the place. Consistent points are important for comparison over time.

The other is not understanding about the range cone of reading.
Try reading from too far away and you will get an average temp from a far larger area than you realize which will throw your efforts in the garbage.

Hoses, rubber parts and shiny whites, chrome or shiny metal will not read well.

All engine have hotter spots than the coolant temp sensor will show.
Good spots, some already suggested.
-right next to temps sensor for coolant but expect to read a few degrees lower
-engine oil pan
-raw water into heat exchanger and out.
-exhaust water elbow
-gear case near oil pickup point to pump

Pick some other spots but just be consistent.

Note also about the cone of reading range. Most have a short range. A 6:1 means the unit will read a 1" diam. spot when 6" away. There are 8:1, 12:1 , 20:1 and so on but the price goes up. Some read a minimum size spot of ~ 1". Some can be adjusted to read other surfaces, emissivity, but most read well only on flat, dark surfaces.
I have an inexpensive unit offered by Mastercool, refridgeration guys, but it does what I want. Just be aware of the limits of the unit you select or it can mislead you.

tegdesign · Oct 8, 2014

captrigney said:
For 30 bucks it doesn't make sense NOT to have one. Here is a guide from Marine Engine Analysis

If you have not used a laser temperature gauge before you’ll be amazed at how much information this simple tool will show us about our engine. (See Tradeaboat April for full use instructions)

Begin by scanning the gearbox looking for hot spots. Pay careful attention to the area of the case around the clutch packs, and the gearbox output bearing. If any part of the gearbox is going to build up heat it will be during this bollard pull test. The complete gearbox should be under 80C, and 60C is typical.

Continue checking with the laser gauge along the cylinder head. It should show about 75-85C everywhere. There should be no hot spots. A hot spot would be more than a five degree C change in the head from one end to the other.

Note-Testing the area directly around the exhaust manifold does not count as a “hot spot”, as this will be hot due to the high temperature of the exhaust.

Check the oil temperature by shooting the oil filter or oil pan. The oil temp should be about 7-10C above the head temperature and not above 95C.

Check the inlet to the salt-water pump and outlet of the final heat exchanger. With most engines the temperature difference should be less than 10C. A higher temperature difference can indicate an engine producing too much heat (IE failing head gasket) or too little water flow (IE clogged salt water system).

Check the fresh water temperature inlet and outlet of the heat exchanger. The difference should be about 10C and stable. You should be able to move the laser along the body of the heat exchanger and show the cooling effect of the heat exchanger. By this method you can see how much reserve cooling you have left in the heat exchanger.

The pre turbo exhaust temperature should be about 300-450C. After turbo it should be a bit lower. Check the exhaust gas temp between the cylinders and exhaust manifold for each cylinder. Normal for a loaded non-turbo engine should be 300C. A cylinder temp lower than the rest shows a clogged injector or maybe a dead cylinder. A high cylinder temp possibly shows a leaking exhaust valve, or poor injector spray pattern.

thank you thank you thank you!!!! actual numbers!!!

Keysdisease · Oct 9, 2014

Me too, Harbor Freight, I do sea trials with certified mechanics to sign off on new installations, we get + - 1-2* next to a Snap-on gun which is twice the size and I'm sure much more expensive.

:socool:

BDofMSP said:
Hi,

I've seen models that range from $20 to $200 so I'm wondering what makes one "good".

Thanks,
BD

Underway · Oct 9, 2014

...works for determining fluid level in holding tanks...

Vashon_Trawler · Oct 9, 2014

markpierce said:
I have one. It is fun to occasionally check the temperatures of the cement docks, the interior of the boat, and the relative temperatures of the boat's various color.

This alone makes me want to buy one. My decks are sometimes so hot from the sun during the summer that I cannot walk barefoot on them. I've been known to spray my concrete dock with water so I can walk on it barefoot.

Anyone ever step barefoot on a sunbaked vinyl cushon! Yikes!

HopCar · Oct 9, 2014

"works for determining fluid level in holding tanks..."
Nice! Thanks for the tip.

You guys have all missed the best use for them, Cat Toy. That laser dot drives the kitties nuts.

r-rossow · Oct 9, 2014

tegdesign said:
thank you thank you thank you!!!! actual numbers!!!

Actual temp numbers will vary from engine model to engine model and how hard you push it (Idle vs WOT).
I used to run MAN D0836 engines that ran steadily at 118C oil temp. Engine oil temp alarm fired off at close to 128C. Exhaust temp was in the 500/600C area.

Get to know your engine. Make a note (mental/paper/log book/etc) of what is normal temp so you know what to compare to. Also look for local hostspots as captrigney points out

IR Temperature gun?

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