Why need auxiliary lamp and how to use auxiliary lamp correctly

1. Why need Auxiliary Lamp and how to use Auxiliary Lamp
correctly?
According to IESNA-LM-79-80, when spectroradiometer integrating sphere system tests LED flux, light
source’s self-absorption can influence test result, therefore, it usually introduces Auxiliary Lamp. The induction of
absorption Auxiliary Lamp can solve the absorption problem of the tested lamp itself.
How to use Auxiliary Lamp correctly? Lisun LPCE-2(LMS-9000A) High precision Spectroradiometer &
Integrating Sphere System for LED has 4 steps for measurement, shown as follow (Yellow states that the lamp is
light state):
Step 1: Import the data of standard lamp, light
standard lamp for system calibration, save the
calibration file;
Step 2: Close standard lamp and don’t remove,
light auxiliary lamp, record the standard lamp’s
absorption condition and save it as calibration file;
Step 3: Change the standard lamp to the tested
lamp, light auxiliary lamp, record the absorption
condition of the lamp under test and save it as
calibration file. Software can automatically calculate
the spectrum self-absorption factor of standard lamp
and the lamp under test;
Step 4: Extinct the auxiliary lamp, light the lamp
under test, choose the calibration files above to do test.
When software calculates the result, it will
automatically compensate back the spectrum
absorption-factor from Step 3 to get the correct result.
This is the requirements of USA Energy Star LM-
79 for Integrating Sphere LED measurement. For a
sphere-photometer system, the auxiliary lamp does not
have to be limited to incandescent lamps. Rather, it is
advantageous to use an auxiliary lamp that has a
spectral distribution similar to those of the SSL
products typically measured, so that self-absorption is
measured accurately especially when the self-
absorption is very large (a<0.8) or when the housing of
SSL product under test is large and strongly colored.
The auxiliary lamp needs to be stable throughout the
self-absorption measurement of all SSL products under test. A stable white LED source, for example, may be
used.
Lisun LPCE-2(LMS-9000A) High Precision Spectroradiometer Integrating Sphere System can test LED
lamps and single LED for CCT, CRI, Spectrum, Lumen, lumen efficient, power, power factor, current and voltage

2. and so on. CIE-127-1997 and IES LM-79-80 Standards recommend using array spectroradiometer together with
integrating sphere to test SSL products. The LPCE-2(LMS-9000A) also can do the LED optical maintenance test
such as Flux VS time, CCT VS time, CRI VS time, Power VS time and so on which is meet LM-80.