I was away from my home for several days.
When I returned, there was a slight smell in about one half of the home.
No matter how hard I try, I cannot locate the source of the smell.

Is there a service that has a smell detector?
Can a smell detector be rented?
Can a smell detector be purchased?

Hi Clicker5-ga

As a person who worked for a pollution control company, I'll try to
give you some ideas on this matter.

"No matter how hard I try, I cannot locate the source of the smell. Is
there a service that has a smell detector?"

If by smell detector you mean to say an odor detecting device that
will readily point you to the source of smell, I believe there is no
such technology yet in existence. The main reason is there are factors
that can affect the accurate detection of the odor's source -- factors
such as ventilation, air flow, presence of deodorants, etc. There are
also instances when odor is almost evenly dispersed in an area due to
any of this factors which makes it very hard to detect the exact
source. So far, we still rely on our noses to get an accurate source
detection and sometimes, by means of that familiar wet nose of man's
best friend, the dog -- which no current odor detector can match in
sensitivity and accuracy.

The smell that greeted you when you returned home may be caused by
many factors. Usually, this kind of odor is musty or stale, which is
caused by bacterial or fungal activity on decaying organic matter such
as left-over food, etc. This bacterial activity produces gases that
pollutes the air and may cause health problems. How can you prevent
this? You need to identify the gases present in the air as well as the
source/s. That's where gas detectors come in handy.

All the gadgets that we call smell or odor detectors are in fact gas
analyzers. All odors are gas and all gases are composed of chemicals.
Some chemicals have odors, some have not. A popular gas detector is
the carbon monoxide (CO) detector. It can't tell us where the source
of the CO gas is, but it can tell us that it's present in the air.
Given this, we can't use odor, because CO gas is odorless. The correct
term we can use now is gas. Notice our transition from smell, to odor,
to gas? :-)

There are many gas detectors in the market today. Some are focused to
a particular odor, gas, some can detect a variety of gases. Take for
example the "Cyranose 320 electronic nose", that was mentioned earlier
by my good coleague, Juggler. It detects and identifies gases present
in the air. It can be customized to a specific application in a given
environment.

Cyrano Sciences Inc.
Cyranose 320 electronic nose
http://cyranosciences.com/products/cyranose.html

Other products
http://cyranosciences.com/products/


Here are sample lists of companies offering products and services
about gas detection and analysis:

Gas Analyzers
http://www.biobank.co.kr/item/gg/gas-anal.shtml

Gas Chromatography, Detector
http://www.biobank.co.kr/item/gg/gc-detect.shtml


"Is there a service that has a smell detector? Can a smell detector be
rented? Can a smell detector be purchased?"

Given the information above, the answer to these three questions is
yes. Since I have no information on where you are located and what
your exact requirements are (your situation may require actual
inspection), you can buy or find the appropriate companies and
services nearest you through the last two links below.


Search strategy:

"odor detector"
://www.google.com/search?q=%22odor+detector%22&cat=&hl=en

"odor detector" buy
://www.google.com/search?num=100&hl=en&lr=&ie=ISO-8859-1&newwindow=1&safe=off&q=%22odor+detector%22+buy

"gas detector" buy
://www.google.com/search?q=%22gas+detector%22+buy&sa=Google+Search&cat=&hl=en

"gas detector" rental
://www.google.com/search?q=%22gas+detector%22+rental&cat=&hl=en

+ personal knowledge


With regards to the source I have given you that may include the
product descriptions, applications, etc., the information came from
the products itself and I'm in no way representing any company    
that you may find in this answer.

I hope this helps you. Should you have any comments/questions, please
feel free to post your clarification before rating this and I'll
attend to you as soon as possible. Thanks for asking.


Best regards,
Feilong

Hello feilong-ga:
Thank you for the answer.
clicker5-ga

Hi!

I was only able to find something in the experimental stage.

"The Artificial Sniffer"
http://www.scs.uiuc.edu/suslick/pdf/pressclippings/newsday.htm

This article is kind of interesting:

"Plenty to Sniff At: Smaller and more sensitive electronic noses open
up new applications"
http://www.sciam.com/article.cfm?articleID=000454C0-FBEC-1C70-84A9809EC588EF21

The $8000 Cyranose that the article mentions can be seen here:
http://cyranosciences.com/products/cyranose.html

If the smell in your house is the sort of odor that a dog might be
interested in, you could borrow a dog, let him loose in the house, and
follow him to see where he goes. Seriously, this can work. We had a
neighbor who complained of a "musty" odor; she borrowed a friend's
dog, and the dog quickly homed in on the source of the smell: a dead,
nearly mummified squirrel behind the drywall in a closet!

Of course, if a dog doesn't find a certain smell intriguing, this
method isn't going to get you anywhere. But one of the best
smell-detectors on earth is at the end of Fido's snoot, and all it
will cost you to rent it is maybe a squeaky-toy and some doggie
biscuits. ;-)

I have done my own research on odor detectors, but the machines I have
found can only indicate the presence of a certain smell, but cannot
lead to the location of the source. A smell-source locator is probably
years into the future. Pinkfreud's suggestion is the most practical
alternative for the meantime, I believe. :)