Bill: 

Condensation inside the OTM 27 cyclone or on the filter should not be a problem if you preheat the cyclones as 

specified in Section 8.6.9. You should not have a condenstaion situation at the end of the sampling period since 

the cyclones and filter assembly will be above the dew point until they reach ambient temperature and if the air is 

super saturated with moisture (your in a fog). At 530 F there should be no water droplets and therefore the

situation where the sampling can not be performed would not exist. There may be a situation with the stack 

temperature that you will need to address. At about 500 F there may be galling of the threads of the cyclone and 

other metal parts. Up to a point you can address this with the sparing use of anti-sieze compound and use of 

metal gasket materials. You should contact the supplier of the cyclones for their recommendations. If they do not 

have a solution for the high temperature condition, then the use of EPA Method 5 as an alternative for OTM 27 is 

the only resolution that we have at this time. In that situation, we would consider that all of the material collected 

on the Method 5 filter is less than 2.5 uM. 

_________________________________

Ron Myers 

U.S. Environmental Protection Agency 

Office of Air Quality Planning and Standards 

Sector Policy and Programs Division 

Monitoring Policy Group, D243-05 

RTP NC 27711 

Tel. 919.541.5407 

Fax 919.541.1039 

E-mail myers.ron@epa.gov 

Ron: 

Please respond to this question about filter temperature and high moisture relative to using OTM 27. 

Thanks, 

Peter 

From: Peter Westlin/RTP/USEPA/US

To: Ron Myers/RTP/USEPA/US@EPA

Cc: "Jill Merrill" <jmerrill@air-comp.com>, "Michael Matvey" <mmatvey@air-comp.com>, "Rob Frey" <rfrey@air-comp.com>, "William 

Ondriezek" <wondriez@air-comp.com>, "William Cowell" <wcowell@air-comp.com>, Jason Dewees/RTP/USEPA/US@EPA, Robin Segall

Date: 07/14/2009 06:09 PM

Subject: Re: Stack Testing Question on a Cement Kiln

From: "William Cowell" <wcowell@air-comp.com>

To: Peter Westlin/RTP/USEPA/US@EPA

Cc: "Jill Merrill" <jmerrill@air-comp.com>, "William Ondriezek" <wondriez@air-comp.com>, "Michael Matvey" <mmatvey@air-comp.com>, "Rob 

Frey" <rfrey@air-comp.com>

Date: 07/14/2009 10:11 AM

Subject: Stack Testing Question on a Cement Kiln

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Peter, 

 

We are a stack testing firm representing a cement kiln client that was notified of its requirement to test PM2.5

under the Section 114 CISWI program. Now, the recommended test method for measuring PM2.5 is OTM27/OTM-28. 

 

However, in reading guidance document 51A http://www.epa.gov/ttn/emc/guidlnd/gd-051A.pdf Q21/A21 and 

Q27/A27 seem to suggest that for wet stacks (entrained moisture droplets), EPA Method 5, followed by an OTM28 backhalf is the preferred alternate. 

 

The source we are testing has an average moisture content between 30 and 35%. Now, the stack air 

temperature is 530+ deg. F, so the moisture is probably not in droplet form in stack, but we feel it likely that the 

filter in the OTM-27 sampling head is prone to get some moisture on it due to the high moisture when removing 

the probe from the stack, thus making the removing/cleanup of the filter and subsequent weighing of the filter 

suspect. 

 

I have pasted a previous stack test program results below to show you the stack properties, and we were looking 

to propose doing a 4-hour Method 5/OTM-28 test instead of OTM-27/OTM-28 for reporting PM2.5 and wanted your 

thoughts on this approach for this source. You were the designated test contact for testing methods, so I directed 

this question to you first. 

 

 

 

 

 

 

 

William Cowell 

Senior Engineer, QSTI 

(412) 826-3636 

Start Time 2:00 PM 7:10 AM 1:55 PM

End Time 6:05 PM 11:15 AM 6:05 PM

Flow Rate (ACFM) 136,694 142,627 145,387 141,570 

Flow Rate (SCFM) 71,843 73,893 76,096 73,944 

Flow Rate (DSCFM) 48,705 49,670 50,762 49,712 

Carbon Dioxide (dry volume %) 16.00 16.00 15.50 15.83 

Oxygen (dry volume %) 9.50 9.50 9.00 9.33 

Water Vapor (volume %) 32.21 32.78 33.29 32.76 

Stack Temperature (°F) 537.1 546.5 539.6 541.1 

Percent of Isokinetic Sampling (%) 97.9 99.9 101.1 99.6

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