Particulate sensing


Thread Starter

Bill Gausman

I'm looking for a way to measure particulates in an exhaust air flow, downstream from a HEPA filter. Any ideas?

Bill Gausman
System One Control, St. Paul, MN

Adolfo Jimmy Saldivias Valarezo

Hi Bill:

There are products manufactured by Land which can do what you are looking for. Specifically the Mark II 4500, is a sensor using green LEDs whose light travels through the stack and reflects back
to the transceiver. The reflected amount of light is compared with the amount sensed and the particulate content is calculated from here. You may check their website at:

Hope this helps
Jimmy Saldivias
Phone: 591-4-523438
Fax: 591-4-523413
downstream of working hepa filters the particulates before agglomeration are less than 0.5micron size. search for the companies making optical particle counters for use in air, such as met-one, pms of boulder colorado, hiac-royco, rion
of japan, etc.


Richard King

Hi Bill,
Not sure of the type of emission you want to monitor, there are many types of instruments. Have a look at the TriboFlow We have used this for Dust Emission from Dust collectors Sensitivity range options available down to .000005 gr/dscf (~.01 mg/m 3 )

Not sure how accurate this device is, we are not using it for accurate readings, just indication. We have also used Opacity Meters (they can have problems, you would need to specify more detail about what you wanted to monitor)

I hope this info helps.

Richard King.

Alesa Alusuisse Engineering Australia Pty Limited.
Phone: +61 7 3218 3555
Fax : +61 7 3236 0155
Email: [email protected]
Web :

Shibu Thomas

You could either use continuous on-line monitoring system or use a Portable Particle counter the latter being more desirable, if the
application is to check the integrity of HEPA filters from time to time.

Important Considerations are :

1) size of Particles to be measured
2) Clean room Classification

MET-ONE has range of Products, Pls check out their web site,


Shibu Thomas
Asst. Manager (Sales)
Prolific Systems & Technologies (P) Ltd,
202, Suchita Industrial Estate, Pokhran Road No. 2,
Thane (W) - 400 601

Tel : 5443307, 5422887
Fax : 5338399, 5422887
E-mail : [email protected]

Dittrich, Rodolfo

For this application there is a sensor that works with the triboelectricity method. I had the opportunity to install a net of this instruments to measure the particulate air coming out from the filter on a boiler (working with sunflower hull as fuel). The instrument work really good and the net was connected to a software for

Instrument: PCME
Model DT270 / 770
from the U.K

You can search on the internet for suppliers


Eng.Rodolfo Dittrich
Proyect Engineer
Electricity & Instruments
Phone : +54 291 4598000 ext. 8205
Fax : +54 291 4598029
E.mail: [email protected]