The method defines the result

Stack Emissions Isokinetic

Environmental Monitoring can stear and advise you on current Isokinetic Monitoring Equipment that meets all current standards.

Particulalry BSEN 13284 and ISO 9096.


BSEN13284-1 is a Low Dust Standard with a Scope that states the standard may be used on process with Emission Limit Values below 50mg/m3.

BS ISO9096

BS ISO9096 is an Isokinetic Standard that states a Emission Limit Value (ELV) of 50-1000mg/m3.

The Most Basic Configuration of an Isokinetic Sampling Kit is as follows:

  1. Isokinetic Nozzle, along Side Pitot Tube and Thermocouple, Closed Coupled to Filter Housing(47mm) and Attached to Sample Probe.
  2. Umbilical with Knocokut System inline between Probe and Sample System.
  3. Sample Metering System with Pump, Meter, Controls and Temp Indicators.

Environmental Monitoring is able to Supply Isokinetic Sampling Equipment and also supply training.

The Second System is the Heated Extractive Sampling System. This uses a Heated Probe and Heated Filter in an Oven Box.

Why use Isokientic Sampling?

Isokinetic comes from the greek word "isos" which means same and "kineo" which means to move

The Objective being that we are Aiming to Obtain a Sample of Dust matter by Sampling at the Same Flow that the Dust is moving up the Stack.

If the Amountor & Isokientic sampling is good i.e near to 100% then we can indicate that the sample is representative of what is being Emitted from the Point Source.

Where would this Equipment be used?

It may be used in Any Stack, Duct that complies with the Sampling Location Requirments i.e the Sampling Plane being located at 5 Duct Diameters upstream and downstream from the nearest obstruction.

The area the sampling nozzle occupies must not be greater than the % specifief by the standard

Useful Historic and Current Reading

US EPA Method five from the code of federal regulations. Why read this- a lot of monitoring equipment in the uk is based around us epa method five isokinetic monitoring equipment.

This method provides excellent mathematical information and calculations. also highly specific diagrams of equipment as well as credible calibration information. Environmental Monitoring recommend you read this.

BS3405 - The old standard which refers to the BCURA this was developed by British Coal/CEGB back in the 1950's.

What are the Basics of Isokinetic Monitoring?

Basically we use a Pitot Tube, which is reasonably accurate, to measure differential pressure and hence flow in the stack.

Along with the differential pressure we measure:Temperature, static pressure, atmospheric pressure, moisture content, gas density of Carbon Monoxide, Carbon dioxide, Oxyegen and Nitrogen.

Differential pressure is measured using a Pitot Tube Couple to a Differential Pressure Manometer( either oil in glass or electronic) the range is typically 0-9cm and the units of dp are either mmH20 or Pascals.

Temperature is meaured using a k-type thermocouple and a digital temperature reader.

Moisture is measured by condensing the water vapour into impinger for 30mins non isokinetically and calculating the % moisture you collect relative to the volume sampled.

Gas make CO,CO2, O2 and N2 is measured using a Combustion Analyser

All of these products are avaialable from Environmental Monitoring

What do we do when we have measured dp, Temperature , Moisture and Combustion Gases?

Once we have measured our dp and hence velocity we can select an Isokinetic Nozzle(Environmental Monitoring supply Isokinetic Nozzles).

The Isokinetic Nozzle is attached to the end of the Probe either using Instack or Heated Extractive Sampling.

Finally when Sampling we need to select the correct Isokinetic Sampling Rate using the Isokinetic Rate equation to Satisfy the Sampling Criteria that Delta P multiply by the isokinetic rate factor = delta H.