LPS-CH-500

Testing of light source flicker properties

Technical report IEC TR 61547-1:2017 requires the conduction of specific electromagnetic immunity tests (EMC). These apply to light sources for general lighting purposes and are especially relevant in case of LED based light sources. The tests consist of a series of electric waveforms which deviate from a stable power supply. Thus, the effect of a disturbed power supply on a light source is checked.

Measurement Setup

The measurement setup according to IEC TR 61547-1:2017 consist of two components:

1. a signal generator,
2. a light measurement device which is able to measure flicker properties.

For this task, Gigahertz-Optik offers the combination of signal generator LPS-CH-500 with either the spectral light and flicker meter BTS256-EF or the high speed transimpedance amplifier PLL-1701.

Measurement Conduction

The light source connects to the signal generator. On the one hand, it supplies the light source with its stable operating current. On the other hand, it applies a number of five electric test signals that disturb stable operation. These signals allow testing of the light source’s emission stability.

The following test signals are applied:

The light and flicker meter measures the light emitted by the light source. An end-user software analyzes both the electric input signal and the measured light signal. This makes calculating the short-term flicker severity P_st^LM possible. Since surrounding light sources may affect the above-mentioned measurements negatively, measurement conduction in a dark room is recommended. 

Both the BTS256-EF and the PLL-1701 allow short-term flicker severity P_st^LM immunity tests according to IEC TR 61547-1:2017 when combined with signal generator LPS-CH-500.

LPS-CH-500 – Waveform generator

Signal generator LPS-CH-500 is equipped ideally in order to conduct P_st^LM immunity measurements according to IEC TR 61547-1:2017. It can supply up to 250 W of power and offers features like power line disturbance simulations and programmable output impedance. Furthermore, it offers support for compliance tests against IEC 61000-4-11 and IEC 61000-4-13/-14/-28.

BTS256-EF – High quality spectral light and flicker meter

The BTS256-EF is a high-quality measuring device for photometric and colorimetric measurement of general lighting products and conditions. It is described in detail on a separate data sheet. 

Among its functions, the BTS256-EF offers the measurement of light flicker. All current flicker measurement quantities are supported:

• Percent Flicker (IES: RP-16-10, CIE:TN-006, CIE:TN-012)
• Flicker Index (IES: RP-16-10, CIE:TN-006, CIE:TN-012)
• FFT Frequency component analysis
• Short term flicker severity P_st^LM (CIE: TN-006, IEC TR 61547)
• Stroboscopic Visibility Measure SVM (CIE: TN-006, IEC TR 63158)
• Flicker perception metric M_p ASSIST

PFL-200 – High speed transimpedance amplifier

Same Technology as BTS256-EF but with BNC connector for direct detector application (-2).

PLL-1701 – High speed transimpedance amplifier

The PLL-1701 optometer is a high speed transimpedance amplifier. It is designed for two different types of fast optical measurements with two different amplifier modes (linear or logarithmic). 

The PLL-1701 can measure signals using the integrated amplifier. It can be connected to a photodiode (e.g. VL-3701-1) and read out the current. This current is processed in one of two ways:

1. It can be processed digitally using an end-user software (S-PLL1701) or the software development kit (S-SDK-PLL1701).
2. It can be converted into a voltage and sent to an oscilloscope. 

Furthermore, the PLL-1701 contains a small integrating sphere with photodiode. A light guide with FC-type connector couples the light into the integrating sphere. The diode’s short rise time as well as the high speed of the transimpedance amplifier allow the signal evaluation regarding flicker.

The PLL-1701 fulfills all specifications the standards NEMA 77-2017 and IES TLA LM demand from a transimpedance amplifier for flicker applications.

Traceable factory calibration

The measurement laboratory of Gigahertz-Optik offers high quality and traceability of their BTS256-EF and PLL-1701 factory calibrations. Gigahertz-Optik’s calibration laboratory handles factory calibrations using the same quality management procedure that applies to NMI accredited test measurements. NMI accredited test measurements with an ISO/IEC/EN 17025 testing certificate are optionally available.