Bowser-Morner's Radon Reference Lab provides spiking services.

Performing spikes involves exposing devices to known and controlled conditions of radon, temperature and humidity.

Project Background

Protocols and standards require radon measurement professionals to assess the accuracy of the devices they use through spikes.  Three out of every one hundred devices are required to be sent to an approved reference laboratory for spiking to known conditions.  The reference laboratory reports the conditions to which the devices were exposed along with the returned devices.  The measurement professional then forwards the devices to the analysis laboratory.  The devices may be coded to look like field samples with fictitious locations, but for charcoal devices (AC and LS) the analysis laboratory must be provided with the actual dates and times the devices were exposed.  The results from the analysis laboratory are then compared to the radon concentration reported by the reference laboratory.

QC Analysis of Spike Results

The relative percent error (RPE) of each measurement is calculated using the following:

RPE = 100 × (MV - TV) / TV

where

MV = measured value from analysis laboratory

TV = target value from reference laboratory

MV and TV must be in the same unit; pCi/L or Bq/m3.  Alpha-track devices are often exposed at the reference laboratory for a shorter exposure time than field samples.  If the analysis laboratory is given an exposure time that matches the field samples, then measurement results must be adjusted for this time difference.

The values of RPE should be placed on a control chart along with control limits.  Control chart guidance can be found in the EPA document Guidance on Quality Assurance, EPA 402-R-95-012, located on the EPA website, www.epa.gov/radon.

 



Client
Various Clients

Location
Dayton, Ohio

Services Performed

Key Personnel