ISTMT it is the measurement of the LED source case temperature within the LED system (luminaire or lamp) while it is operating in it designed position and or environment (In “SITUation”). The measurement is performed at the temperature measurement point (Tc Point) indicated by the LED package manufacturer.
Who can perform testing?
OSHA approved NRTLs or DOE CALiPER Recognized or UL Data Acceptance Program laboratories or NVLAP Accredited laboratories for UL1598 Sec. 19.7 and 19.10-16. It is typically performed at the same time as LM-79-08 testing. All GREEN CREATIVE products go through ISTMT in a recognized laboratory and reports are typically available upon request from the luminaire manufacturer.
What does it provide?
ISTMT is the basis for lifetime interpolation either based on TM-21-11 calculations or by other approved methods.
LED In-Situ testing Information
LED chip/package manufacturer and model number
LED chip spec sheet and if possible LM-80 report information
Diagram showing where to attach thermocouple (Tc); usually in the LED chip/package spec sheet or
Test voltage, current and wattage
Driver model number and specification
Additional measurement information required; i.e. additional Tc’s or driver measurement point(s)