Document ID: chunk:federal_register_of_legislation:F2025L00263:clause:2_5:p4
Version: federal_register_of_legislation:F2025L00263
Segment Type: clause
Provision Reference: sch 2 cl 5 (pt 4/11)
Character Range: 16964–19716

in at least one plane through the lamp axis when luminous flux is measured using all forward-facing lumens.
displacement factor, DF or cos φ1 means a factor expressed by cos(φ 1), where φ1 is the phase angle between the fundamental of the mains supply voltage and the fundamental of the mains current, and is calculated from the ratio of the absolute value of the fundamental active power (P1) to the fundamental apparent power (S1), as follows

as measured:
 (a) at full-load, in the reference control settings (where applicable); and
 (b) with:
 (i) any lighting control parts in control mode; and
 (ii) any non-lighting parts disconnected, switched off or set to minimum power consumption according to the manufacturer's instructions.
double-capped lamp means a lamp with 2 separate caps.
Note: This includes double-capped retrofit LED lamps and double-capped conversion LED lamps, as defined in IEC 62776:2014, clauses 3.1 and 3.2.
excitation purity or pe means the quotient NC/ND of the following two collinear distances on the chromaticity diagram of the CIE 1931 or 1964 standard colorimetric systems:
 (a) the distance between the point C representing the colour stimulus considered and the point N representing the specified achromatic stimulus;
 (b) the distance between the point N and the point D on the spectrum locus at the dominant wavelength of the colour stimulus considered;
leading to the following expressions:

and

where (x, y), (xn, yn), (xd, yd) are the x, y chromaticity coordinates of the points C, N and D respectively.
Note 1: In the case of purple stimuli, the monochromatic stimulus is replaced by a stimulus the chromaticity of which is represented by a point on the purple boundary.
Note 2: The formulae in x and y are equivalent, but greater precision is given by the formula which has the greater value in the numerator.
Note 3: The excitation purity has unit one.
flicker:
 (a) means the perception of visual unsteadiness induced by a light stimulus the luminance or spectral distribution of which fluctuates with time, for a static observer in a static environment; and
 (b) is expressed in the metric 'Pst LM', where 'st' stands for short term and 'LM' for light flickermeter method, as defined in IEC TR 61547-1.
Note 1: The fluctuations of the light stimulus with time include periodic and non-periodic fluctuations and can be induced by the lamp itself, the power source or other influencing factors.
Note 2: A value Pst LM = 1 means that the average observer has a 50% probability of detecting flicker.
full-load means the condition of an LED lamp, within the rated operating conditions, in which it emits the maximum (undimmed) luminous flux.
HLLL: see high-luminance LED lamp.
high-luminance LED lamp or HLLL