How to Measure the High Frequency Fluorescent Lamp
High frequency fluorescent lamp came out in 1990. Fine tube, small current and high power is the distinct features. Because of the above design structure, high frequency current working, electronic ballast with low power consumption, the work system of this high frequency fluorescent lamp is superior to the traditional lamp on the aspect of lighting effect and photometric.
How to measure the characters of the fluorescent lamp in high frequency condition? How to verify the match relationship of the tube and ballast? These problems always trouble the fluorescent tubes manufacture enterprise and the third lab service company. Lisun Group supplies the following two solutions: IEC Standard Test Method and High Frequency Constant Current Equivalent Test Method.
1. IEC Standard Test Method:
Double end fluorescent lamp adopts the IEC 60081 (GB/T10682) and the single-ended fluorescent lamp adopts the IEC60901 (GB/T17262), where in the standard of electricity parameters as in Fig 1. As we know the testing correctness of the photo & color parameters are based on the fact that the reference ballast, power and instrument in the detection circuit all comply with standards. If the reference ballast, power and instrument can’t meet the standard that means it can not supply the tube with standard working conditions. Then, not only the tested electricity parameter but also the photo & color parameters will deviate from the actual value obviously.
Fig 1 Preheating Method of Cathode High Frequency Fluorescent Lamp
Fig 1 does the high frequency tube test based on IEC Standard which required the High Frequency Power Source, Adjustable Reference Ballast and Lamp Preheat Assistant Source.
●High Frequency Power Supply (HFP-800): output power is 20～26kHz, the frequency should be kept in the range of ±2％ at working. Output power is 0～580V.
●Adjustable Resistance Ballast (RB-3): impedance values of high frequency reference ballast which used by any high frequency lamp with regard to GB/T10682 (IEC 60081) and GB/T17262 (IEC60901), RB-3 conforms to the requirement of IEC60929.
●Lamp Preheat Assistant Source | Auxiliary Power Supply (LPS-3): Preheating method of cathode during the high frequency fluorescent lamp starting.
The above IEC Standard Test System is the necessary instrument not only to measure the photo & electricity parameters according to the standard of IEC 60081 and IEC60901, but also to test the lumen and color parameters according to the standard of IEC60929 (GB/T15144). Any national lighting electrical test centers must adopt the above test system if they need to do High frequency lamp such as T5 tube.
2. High Frequency Constant Current Equivalent Test Method:
Even though, the above Standard Test System can totally conform to the requirement of measuring the high frequency fluorescent lamp by IEC standard, due to the high price of this system, the small third lab service company and the most of manufactory company can’t cover the high cost, Lisun Group developed HCS-105A which is an equivalent test method in comparison with IEC method. The typical schematic is shown as Fig 2, high frequency constant current source provides a continuously adjustable output current of 100mA ~ 500mA.
Fig 2 High Frequency Constant Current Equivalent Test Method
When connecting the circuit to turn on the lights, high frequency constant current source will deliver high-voltage pulse to start the lamp, the output frequency of high frequency constant current source is in 20～26kHz. The obvious shortage of equivalent method is due to the high constant current source output internal impedance. The large internal impedance of high frequency constant current source will cover the departure of tested lamp with respect to standard electrical parameters. It will take about 5%~ 30% tolerances when using LPCE-1 Fig 3 to test the photo, color and electricity parameters.
The above HCS-105A equipped with Spectrophotometer Integrating Sphere Test System (LPCE-1) can test CCT, CRI, Spectrum, Lumen and electricity parameters for high frequency fluorescent lamp T5.