A U.S. study about radiant flux testing of electric infrared heaters


It all started in 2005, when the U.S. Consumer Product Safety Commission (CPSC), under the lead of the author of this article,  conducted a study on radiant flux measurements of electric infrared heaters.  

For the purpose of that study, the definition of such an electric infrared heater is one whose primary means of heating is the emission of infrared radiation. During the 2005 study, a flux map was developed for each heater by measuring the radiant flux in various distances across the heater surfaces. The study established that such measurements are possible with a relatively simple measurement method, based on a common Schmidt-Boelter radiant flux sensor.


As a follow-up to the 2005 study, the U.S. Consumer Product Safety Commission (CPSC) conducted another study in 2007, again under the lead of the author of this article. The intend of this study was to determine if there are practical difficulties involved in making the results of radiant flux measurements on electric heaters repeatable. The outcome of this study was documented in 2008 in the CPSC publication

Flux Mapping of Radiant Electric Heaters: Repeatability Considerations“.


The objective of the 2008 study was to provide additional data to the UL Standards Technical Panel 1042 task group, which was established back then to examine the potential uses of radiant flux measurements for standards development. Many of the performance tests in the UL Standards

UL 1278 (Movable and Wall- or Ceiling-Hung Electric Room Heaters)  and

UL 2021 (Fixed and Location-Dedicated Electric Room Heaters)

have practical inconveniences associated with them. Also, the performance tests in those UL Standards are only qualitative in nature, thereby the test results relying somewhat on the discerning person of the tester.


In order for an objectively quantifiable test method to be included into a Standard that measures the radiant flux of an electric infrared heater, the practicality of the testing method as well as the uncertainty and repeatability of the test results would need to be established.  This was accomplished and documented in the aforementioned 2008 study report.


Click here to download the 2008 study report.



Mr. Randy Butturini, PE
U.S. Consumer Product Safety Commission (CPSC)
Electrical Program Area Team Leader
Bethesda, Maryland, USA

September 2016