Mandatory Calibration and Testing for SmokeStack Testing Equipment (US EPA Methods)

Document ID: AERHQWW-ecy1-en
Last revised: 1, 23.07.06

This page contains a summary of the mandatory calibration (and testing) required for equipment used in the United States Environmental Protection Agency (US EPA) methods for smokestack testing "stack testing" and isokinetic sampling on stationary sources of air pollution. These methods are usually from the US EPA Office of Air and Radiation (OAR).

For smokestack testing (and especially isokinetic sampling), the sampling procedures are more important than the analytical procedures. This is because of the difficulty in getting a representative sample of the flue gas inside the smokestack. The pollutants could be in solid, liquid, or gaseous states, or a mixture (e.g., solid in gas) which is not well mixed, and with many other interferences.

We strongly recommend attaching proof of the below calibrations and tests/verifications to the final smokestack testing report.

Notes:

Please note that this page will be focusing on the more uncommon calibrations and tests, which are special to smokestack testing.
This page is based on what is written in the various US EPA Methods. Refer to local authorities for actual local rules!

Other useful links:

Aer Sampling Basic Training Video with names of equipment and their individual components
Click here to download free copies of all smoke-stack testing methods (latest revisions), at the website of the Air Emission Measurement Center (EMC), US EPA
Why is calibration important? Click here to link to YouTube videos:

Video 1 (English; US Navy)
Video 2 (English; Omega Engineering)

To return to Aer Sampling's Smokestack Testing Encyclopedia content page, click here, or scan the QR Code below:

Overview of this webpage:

Images of entire sampling train of equipment for US EPA Method 5 etc.
Table of mandatory calibrations

Dry Gas Meter (DGM)
Critical Orifices (to calibrate DGM)
Temperature Sensor
Thermocouple Simulator (to calibrate Temperature Sensor)
Internal Diameter Micrometers (to test Sampling Nozzle)
Calipers (to test S-type Pitot Tubes)
Angle Indicator or Inclinometers (to test S-type Pitot Tubes)
Profile Projector or equivalent (to test S-type Pitot Tubes)
Barometer
Mercury Barometer (to calibrate Barometer)
Field Balance
Analytical Balance
Flue Gas Analyzers
Other Analytical Instruments

Table of mandatory tests/verifications

Leak Check - Pitot Line
Leak Check - Sampling Gas Line
Leak Check - Meter Console (Vacuum side, "Front-Half")
Leak Check - Meter Console (Pressure side, "Back-Half")
S-type Pitot Tubes - Assembly
S-type Pitot Tube - Isolated
Sampling Nozzle

Optional Calibrations

Timer
Manometers, or Pressure Gages
Flow rate measuring devices
Probe Heater
Instrument to calibrate Probe Heater
S-type Pitot Tubes
L-type (Standard) Pitot Tube

Table of mandatory calibrations (click individual item for details):

Including calibrations to ensure metrological traceability

What to calibrate

Frequency

Calibrated Against

1. Dry Gas Meter (DGM), inside the Meter Console

After each field use

Refer to:

US EPA Method 5, Section 10.3.2
US EPA Method 17, Section 10
US EPA Method 23, Section 10.1
US EPA Method 201, Section 5.3.1
And many others

Choose one of the below options:

Critical Orifices (easiest option)
Reference Dry Gas Meter "Dry Test Meter"
Wet Gas Meter "Wet Test Meter (WTM)"
Bell Spirometer "Bell Prover"

Refer to:

US EPA Method 5, Section 10.3, 16.1, 16.2
US EPA Method 23, Section 10.1
And many others

2. Critical Orifice (to calibrate DGM)

Periodically

(Recommended: Annually)

Refer to:

US EPA Method 5, Section 10.3.1, 16.1 and 16.2
US EPA Method 23, Section 10.1
US EPA Method 26a, Section 10.1
US EPA Method 29, Section 10.1
Etc.

Varies

Refer to:

US EPA Method 5, Section 16.2, 16.1, 10.3
Etc.

Click here (or scan QR Code below) to view Aer Sampling's traceable calibration service for Critical Orifices

3. Temperature Sensor, inside the Meter Console

Need to calibrate every thermocouple connected to Temperature Sensor (via all the thermocouple plugs and sockets)

After each field use

Refer to:

US EPA Method 5, Section 10.5
US EPA Method 2, Section 10.3.1
US EPA Method 23, Section 10.1
Etc.

Thermocouple Simulator etc. (US EPA Method 2, Section 10.3.1)

4. Thermocouple Simulator "Thermocouple-Potentiometer Systems" (to calibrate Temperature Sensor)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

5. Internal Diameter Micrometers (to test Sampling Nozzle)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

6. Calipers (to test S-type Pitot Tubes)

Refer to:

US EPA Method 5, Section 10.2
US EPA Method 2, Section 10.1 and 10.1.1 (except Figure 2-2, Pa = Pb)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

7. Angle Indicator or Inclinometer, with Bull's Eye Level (to test S-type Pitot Tubes)

Refer to:

US EPA Method 5, Section 10.2
US EPA Method 2, Section 10.1 and 10.1.1 (except Figure 2-2, Pa = Pb)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

8. Profile Projector "Optical Comparator", or Microscope with image analysis software, or equivalent (to test S-type Pitot Tubes dimension Pa and Pb)

Refer to:

US EPA Method 5, Section 10.2
US EPA Method 2, Section 10.1 and 10.1.1 (specifically for Figure 2-2, Pa = Pb)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

9. Barometer

Varies

Refer to:

US EPA Method 5, Section 10.6
US EPA Method 23, Section 10.1
Etc.

Mercury Barometer (US EPA Method 5, Section 10.6)

10. Mercury Barometer (to calibrate Barometer)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

11. Field Balance

Used for weighing contents of impingers

Daily before use

Refer to:

US EPA Method 5, Section 10.7
US EPA Method 23, Section 10.1
US EPA Method 29, Section 10.4
Etc.

ASTM E617-13 Class 6 Weights or better

12. Analytical Balance

Used for weighing filters

Multi-point Calibration: Before first use, and semiannually thereafter

Single-point Calibration: Each day it is used

Refer to:

US EPA Method 5 (December 7, 2020 revision), Section 10.8

ASTM E617-13 Class 2 tolerance (or better) calibration weight that corresponds to 50 to 150 percent of the weight of one filter, or between 1 g and 5 g

13. Flue Gas Analyzers

Wet-Chemistry Type (Orsat, Fyrite)
Instrumental Type (NDIR, electrochemical etc.)

Wet-Chemistry Type (Orsat or Fyrite):

Periodically
Refer to:

US EPA Method 3, Section 10.1 and 11.3

Instrumental Type:

Initially

3-point calibration error test (US EPA Method 7e, Section 8.2.3)
"System bias" or "system calibration error" (US EPA Method 7e, Section 8.2.5)

Before and after each sample taken ("each run")

"System Bias", or "System Bias Calibration Checks" (US EPA Method 7e, Section 8.5)

Refer to:

US EPA Method 3a Section 10.0
US EPA Method 7e, Sections 10.0, 13.0 (Replace NOx in text with O2 or CO2 etc.)

Wet-Chemistry Type (Orsat or Fyrite):

Known mixture of CO2 and O2 (US EPA Method 3, Section 10.0)

Instrumental Type:

US EPA type certified calibration gases

US EPA Method 3a, Section 10.0
US EPA Method 7e, Section 10.0 (2)
US EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards
US EPA Method 205 (If diluting calibration gases)

14. Other Analytical Instruments

High Resolution Gas Chromatograph/Mass Spectrometer (HRGS/HRMS) (US EPA Method 23, Section 10.2 etc.)
Ion Chromatograph (IC) (US EPA Method 26a, Section 6.3.3 etc.)
Atomic Absorption Spectrometer (AAS) (US EPA Method 29, Section 6.3.12 etc.)
Etc.

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

Related topics: ISO/IEC 17025, ILAC MRA, scope of accreditation, stationary/fixed sources of air pollution

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List of mandatory tests/verifications (click individual item for details):

What to test/verify

Frequency

Test Using

1. Leak Check: Pitot Line

Consist of three items: Pitot Tubes, Pitot Tube connections (Umbilical Cable), Manometers or Pressure Gages (inside Meter Console)

After each sample taken (each sampling run), before dismantling the sampling train

Refer to:

US EPA Method 5, Section 8.5.9
US EPA Method 23, Section 8.1.5
Etc.

Manometers or Pressure Gages); Analog or Digital), which is inside the Meter Console

2. Leak Check: Sampled Gas Line

From the Sampling Nozzle to the pump valves and fittings inside the Meter Console

After each sample taken (each sampling run), before dismantling the sampling train

Acceptable leak rate:

Leak check must be done at a vacuum equal to or greater than the maximum vacuum reached during sampling.

Leak rate must be no greater than 0.00057 m3/min (0.020 ft3/min), or 4% of average sampling rate, whichever is stricter.

Refer to:

US EPA Method 5, Section 8.4.4
US EPA Method 23, Section 8.1.4
Etc.

Dry Gas Meter (DGM), which is inside the Meter Console

3. Leak Check - Meter Console (Vacuum Side, "Front-Half")

From the Sampled Gas inlet to the pump valves and fittings inside the Meter Console

When needed (example: before calibration of DGM without the entire sampling train)

Acceptable leak rate:

Leak check must be done at a vacuum equal to or greater than the maximum vacuum reached during sampling.

Leak rate must be no greater than 0.00057 m3/min (0.020 ft3/min), or 4% of average sampling rate, whichever is stricter.

Dry Gas Meter (DGM), which is inside the Meter Console

4. Leak Check - Meter Console (Pressure Side, "Back-Half")

From the pump valves and fittings to the Orifice Meter (downstream after the DGM)

After each shipment

Refer to:

US EPA Method 5, Section 8.4.1
US EPA Method 23, Section 8.1.4
Etc.

Manometers or Pressure Gages); Analog or Digital), which are inside the Meter Console

5. S-Type Pitot Tube - Assemblies

(in an assembly with other components like the nozzles, thermocouple etc.)

After each field use

Refer to:

US EPA Method 5, Section 10.2
US EPA Method 2, Section 10.1.5.2.2
US EPA Method 23, Section 10.1
Etc.

Choose on of the below two options to test the pitot tubes:

Option B1) Calipers, Angle Indicators or Inclinometers, Profile Projectors or equivalent etc. (US EPA Method 2, Section 10.1.1)

Option B2) Wind tunnel etc. (US EPA Method 2, Section 10.1.2, 10.1.3, 10.1.4)

6. S-Type Pitot Tube - Isolated

(by itself, without nozzles, thermocouple etc.)

After each field use

Refer to:

US EPA Method 5, Section 10.2
US EPA Method 2, Section 10.1.5.2.1
US EPA Method 23, Section 10.1
Etc.

Choose on of the below two options to test the pitot tubes:

Option B1) Calipers, Angle Indicators or Inclinometers, Profile Projectors or equivalent etc. (US EPA Method 2, Section 10.1)

Option B2) Wind tunnel etc. (US EPA Method 2, Section 10.1.2, 10.1.3, 10.1.4)

7. Sampling Nozzle

Before each use

Refer to:

US EPA Method 5, Section 10.1
US EPA Method 23, Section 10.1
Etc.

Internal Diameter Micrometers

Optional Calibrations

These are calibrations that are:

not mentioned inside the various US EPA Methods, or
not used to calibrate other instruments, or
not necessary because some other conditions mentioned in the methods have been met

What to Calibrate

Frequency

Calibrated Against

1. Timer

(Used to countdown to sampling at the next traverse points inside the smokestack)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

2. Manometers, or Pressure Gages

(Used to measure pressure head "Delta P" of flue gas inside smokestack, which is then used to calculate velocity)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

3. Flowrate measuring devices

Orifice Meter (Orifice Tube, Meter Orifice), downstream of the Dry Gas Meter (DGM)

Used as a guide to adjust the pump valves, to vary velocity of gas entering sampling nozzles
Refer to US EPA Method 5, Section 9.2.1

Rotameters (If in use)

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

4. Probe Heater

Varies

Not applicable if probe heaters has outlet temperature monitoring capabilities

Refer to:

US EPA Method 5, Section 10.4
US EPA Method 23, Section 10.1
Etc.

Varies (US EPA Method 5, Section 10.4)

5. Instruments used to calibrate Probe Heater:

Varies

Refer to Administrator

(Regulatory Agencies or ISO/IEC 17025 Technical Assessors)

Varies

6. S-type Pitot Tubes

Whether in an assembly, or isolated

If S-type Pitot Tubes fail construction specifications

Refer to:

US EPA Method 2, Section 10.1, 10.1.1 and 10.1.5

L-type Pitot Tube in a Wind Tunnel

Refer to:

US EPA Method 2, Section 6.7
US EPA Method 2, Section 10.1.2 to 10.1.4

7. L-type (Standard) Pitot Tube

Other names: Prandtl Pitot Tube

If L-type (Standard) Pitot Tubes fail construction specifications

Refer to:

US EPA Method 2, Section 6.7

L-type Pitot Tube in a Wind Tunnel

Refer to:

US EPA Method 2, Section 6.7
US EPA Method 2, Section 10.1.2 to 10.1.4

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