19 replies to this topic

[Joven76]

Oh boy... A new topic!!! Woo hoo...

I'm looking at buying a new piece of equipment and have decided on a digital thermometer... Now, here's my prediciment, I've read that the "gun" style, laser pointer digital thermometer is ok but the laser has to hit an object and bounce back in order to get a temperature reading... That to me says it won't detect cold spots in the air... It only detects the temperature of what it bounces off of...

So I've been looking at the thermometers that have probes attached, and have a couple models in mind... But I'd like to get everyone else's opinion... What kind do you have, what experiences have you had, and what are your recomendations???

Thanks...

Christopher

[Tantric Kitten]

It depends on what you want it for. There are some "gun" style thermometers that will read the average temperature along the entire length of the laser (so even though they hit an object and bounce back, if the temp's lowered in the air it will still register lower).

If you feel a cold spot and want to check temp... a probe is probably the way to go. If you want the ambient temp in the room or to check when a team member says it's cold, a laser is fine.

[Joven76]

I'm actually looking for both, so I may be looking for both kinds... I've also heard about Thermocouple Thermometers... Anyone use these???

[OMPRDave]

I bought a meter that was recommended on one of the other forums, and it works SPECTACULAR. It's a multimeter, and not only does it read temperatures and relative humidity at the meter, but it also came with thermocouple k-type probes for spot temperature readings. I noticed that the thermocouples aren't ultra responsive to temperature changes, so I only use the base itself.

This is the model here...shop around...I paid $35 with shipping off of eBay back in January.

Other neat features are a backlit display, a pop-out stand so you can set it by itself, and heck, you can even test your home wiring and other electronics projects with it!

This is a similar model, and the price is excellent for all it does: Mastech multimeter

Also, the Mastech homepage has some other really cool environmental meters. All the K-type meters seem to have a 40 second delay before the readings change, however where some are data logging, they may very well be worth the money if it can save one all that time in having to write fluctuations down during the investigation.

Check them out...I'm quite pleased with mine.

Blessings,

Dave

[GPPI_JMe]

I would be interested in hearing exactly how a laser emitting, infrared thermometer detects temperature throughout the entire length of the laser.. How many separate read outs would you need for it to detect just the length of say..6 feet? And the longer you shoot this laser, the more read outs you would need, unless it's averaging the temperature for you. In that case, it would be pretty much useless in detecting the actual cold spot, would it not?

Aside from that, the red laser being projected isn't what's reading the temperature information (that is emitted to show you what object you are checking the temperature of). It's actually the infrared light that shoots out of the thermometer, that then reflects off of the surface, that is giving you information. At least, this is what I've read about these units. I have found that these are useless in detecting ambient temperature changes, as the IR beam can't reflect off of the air itself. However, they can be useful in detecting temperature fluctuations on objects that are manipulated (such as setting a ball out to be moved be a spirit, etc.).

My suggestion, even though there are many models out there with small metal probes that are capable of giving ambient readings (however I have read that these units tend to take a second or two to change or catch up), is to look into the TIF ET7000. This thermo coupler checks the temperature three times per second. That's actually quite impressive, considering how fast some of these alleged cold spots tend to move. If you're looking for accuracy and speed, the TIF is definitely the way to go.

Keep an eye out on eBay, and you can also search Google for the exact model number - ET7000 or TIF ET7000. Some of the best prices out there are found through searching for model numbers, rather than generic descriptions that often take you to mark up ghost hunting supplies stores. I got my unit from eBay for $65 shipped, and it was in perfect shape! In fact, it even came with the original hard plastic case, with cut foam insert to store the unit, as well as a solid attachment probe to use on surfaces, and a liquid attachment probe to use in fluids (and obviously the air attachment probe for ambient fluctuations).

Just my two cents - and I hope to hear back about these laser IR thermometers, as I could be misinformed on them and meant no disrespect in my comments about them!

Edited by GPPI_JMe, 30 June 2008 - 09:17 PM.

[Joven76]

Actually JMe... That's exactly what I've heard... I've even heard that the laser IR thermometers doesn't take the actual temperature, but average temperature... Because the farther you go away from the unit the more the IR signal is spread out...

I'll take a look at that model you mentioned... It looks like that's the way I'm headed as far a a thermometer goes...

Thanks again...

Christopher

[CaveRat2]

The laser light is only used to aim the beam, the actual reading is taken of the surface the beam is striking. No reading is taken on the ambient air temperature. You can do an experiment to prove it. Set a pan of water on the stove and bring it to a boil. When the steam is going good, shoot the beam through the steam against the wall behind the stove. You'll read the temperature of the wall, not the steam.

You need a thermocouple type to read ambient air temperature. Thermal hysteresis is a problem with those. That is the time lag needed for the thermocouple to respond to temperature changes. That is one consideration when choosing type of thermocouple. You will be looking at several seconds up to minutes in response time. Choose accordingly. The fastest response is a platinum wire sensor, these are usually a matter of just a few seconds. Downside is the unit itself and sensors are expensive, $300 and up. Also they are delicate since the wire in the sensor is easily broken. Thay is why they are not often used. However most sensors use a platinum curve, that is they are made to perform like platinum, however this does add to their mass which is why the slower response time.

If you want to read more on theory, and see a wide selection of equipment, go to

Omega Temperature Measurement Meters

You can also go to their main page and read up on theory under various subtopics

Omega Home Page

I have used their test equipment and had satisfactory results. Some is not cheap, but the selection and quality is good. They also have other equipment that some have asked about like dataloggers, which can also be used as recording temperature monitors, humidity , etc. Spend some time surfing their site for more.

[DeadTrish]

Ok here is what I know. I have a "gun" type non-contact infrared thermometer as well as an ambient thermocouple with type K probe. Can you guess which one never comes out of my case? I have a laser on my non-contact. The misconception about the laser is that it reads the temperature. This is untrue. At least in the case of the type that I have. The laser is just meant as a guide so you know what you are taking the temperature of. What I didn't see mentioned either, forgive me if I missed it (very possible), is that it measures surface temperature only. It doesn't measure the room temperature. If you want to know the temperature of the wall in front of you then this is the thermometer for you. I've found a new use for this but it's not for ghost hunting. It's great for tempering chocolate. (sorry, I'm a pastry student)

I use my other thermometer for ghost hunting though. It measure ambient air temperature. It's actually quite fast too in the response time. Hardly any lag. I've tested this too. It's great for sticking the probe in cold spots directly.

I also use some weather stations and data loggers. The weather stations, not noted for fast response times, are good for base readings and constant readings. Not reccommended for determining cold spots or actual investigation. My data loggers record the temperature throughout the night. I have alarms set on it so it will tell me if it has dropped or exceeded the parimeters set (by me) It also has a sample rate of 10 seconds (also set by me) It gives me a nifty little chart when I'm done with it and it helps in conjuction with my other pieces to fill in the gaps if nes. I hope this helps.

[Joven76]

My data loggers record the temperature throughout the night. I have alarms set on it so it will tell me if it has dropped or exceeded the parimeters set (by me) It also has a sample rate of 10 seconds (also set by me) It gives me a nifty little chart when I'm done with it and it helps in conjuction with my other pieces to fill in the gaps if nes. I hope this helps.

In my research, I have found out about data loggers and have been looking into those as well... What kind would you recommend???

[DeadTrish]

Well I am still testing mine but it's pretty simple and it gives me what I need. This is the one I have.

Data Logger Store

We use both the regular temperature one and the one that aslo reads relative humidity.

[OMPRDave]

Great link, Trish. I hope to get a couple of the temp/humidity loggers as soon as the gas prices drop...may be waiting a while...hehe.

Thanks!

Dave

[GPPI_JMe]

I picked up a couple MA-Line loggers (Model number: MA-16540). They were very cost effective, the cheapest on the market from what I've found, and seem to do quite nicely. Run a search for the actual model number and you should turn up a good price!

[jmander]

Interesting thread...quick question though. I've been looking into getting a multimeter for measuring ambient temperature and coldspots myself. When the advertised features on some say "Data Hold", does that mean it will log data? And if not, can anyone recommend a model of multimeter that does offer data logging? Sorry, I'm new to the exciting world of multimeters!

[Joven76]

I picked up a couple MA-Line loggers (Model number: MA-16540). They were very cost effective, the cheapest on the market from what I've found, and seem to do quite nicely. Run a search for the actual model number and you should turn up a good price!

I've been looking at those too and perhaps getting ones that measure the pressure as well... I'm also in the market for EMF data loggers now as well... So in 1 room we'll have a laptop with an EMF, Temperature, and Pressure data logger, recording audio from a stereo microphone and video from an IR camera... That room will be monitored very well... LOL... Too much equipment to buy and absolutly no money!!!!

[Joven76]

Interesting thread...quick question though. I've been looking into getting a multimeter for measuring ambient temperature and coldspots myself. When the advertised features on some say "Data Hold", does that mean it will log data? And if not, can anyone recommend a model of multimeter that does offer data logging? Sorry, I'm new to the exciting world of multimeters!

My assumption is that "Data Hold" is that it will hold the data displayed for a short time, but not actually log it... That is unless it's a data logging model... But that is just an assumption... I could be gravely mistaken...