SU1660069A1 - Method of non-destructive testing of high-pressure mercury gas discharge lamp electrodes - Google Patents

Description

The invention relates to the electrical industry and can be used to test mercury high-pressure discharge lamps. The aim of the invention is to reduce the time of testing and increase the efficiency of the method. This is achieved by connecting the lamp to the AC circuit and choosing the time to turn it on in the range from 3 s to 2.5 min and a cooling pause until the temperature of the lamp walls reaches 2030 ° C. 2 Il.

The invention relates to the electrical industry and can be used to test mercury high-pressure discharge lamps (RGRL VD) of the type DRL, DID and the like.

The purpose of the invention is to reduce the time of testing electrodes RGRL VD from the point of view of their resistance to spraying, saving electricity, obtaining information that does not depend on the instability of the transmittance of the film, quartz glass, as well as the instability of the discharge channel radiation.

This goal is achieved by the fact that the switching cycles are selected in time in the range from 3 s to 2.5 min, and the cooling pause is chosen until the walls of the lamp reach 20 ° C.

Providing the specified mode of cyclic inclusions increases the duration of the operation of the electrodes in the mode of glow discharge with large discharge currents, which allows to reduce the time of the test of electrodes for resistance to sputtering.

FIG. 1 shows a diagram of the device for implementing the method; in fig. 2 - dependence of the amount of sprayed substance on the inner surface of the burner M, rel. units, the duration of the connection of the burner to AC Hvkl.

A device for implementing the method comprises a source of 1 monochromatic radiation (laser type Lg-52.3), a modulator 2, beam splitting plates 3 and 4, a band-shaped beam forming unit 5, a photodetector 6, recording the radiation power of the source, seat 7 for the lamp, collecting lens 8, focusing past in the near-electrode pro IV 6900991

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the radiation in the plane of the photodetector 9, the photodetector 10 of the radiation transmitted in the middle of the burner, the electronic unit 11 of the signal processing proportional to the transmittance of the quartz glass of the burner, the same electronic unit 12 of the signal processing proportional to the transmittance of the quartz glass of the burner and the deposited film, the electronic unit 13 of the selection a signal proportional to the transmittance of the film, the registering device 14, the unit 15 for setting the burner on cycles and the cooling unit 16.

The method is as follows.

The lamp is mounted on the seat 7 so that the ribbon-like laser beam formed by the optical system (unit) 5 consisting of cylindrical lenses passes in the near-electrode space of the lamp along the axis of the lamp (beam width is about 1 cm). A tape-like beam is formed to average the transmittance of the sprayed film, which has a variable density along the lamp axis. At the other end of the lamp there is a cooling block 16 (for example, a fan) 16, with a beam-splitting plate 4 a laser beam is directed to the middle of the lamp. The unit 15 for setting the switching cycles connects the lamp to the mains voltage for the time of complete evaporation of mercury from the lamp walls (approximately 10 minutes). After the lamp is disconnected from the power supply, the unit 15 connects the cooling fan 16 to form a cold zone at the end of the lamp opposite to the measured near-electrode space. Thus, the possibility of mercury film deposition in the near-electrode space, where the laser beam passes, measuring the transmittance of the film of electrode materials, is excluded. Data instability due to instability of the mercury film deposition is also excluded. The power cycle setting unit is programmed for the activation time in the range from 3 seconds to 2.5 minutes and the lamp cooling time to 20-30 ° C. The specific cooling time depends on the cooling conditions. The cycle task block is turned on, and the periodic connection of the lamp to the AC mains begins. After disconnection from the network, the transmittance of the sprayed film is measured, without waiting for the lamp to cool, so that the possible deposition of the evaporated substance does not impair the accuracy of the data obtained. Carry out further switching on and cooling of the lamp using the task block

switching-on cycles and measurement of the absorption coefficient of the deposited film until the deposition of electrode materials is confidently determined. The resulting value of the change in transmittance is divided by the number of inclusions and get the value of change in transmittance for one inclusion, which characterizes the rate of formation of plaque from the materials of the electrodes or the resistance of the electrodes to sputtering.

Used in the device for the implementation of the proposed method, a mechanical modulator is required to modulate the probe radiation and its subsequent separation from the constant component of noise. The electronic units 11 and 12 are similar and produce the division of the transmitted signal by the magnitude of the signal proportional to the intensity of the incident radiation. Thus, the magnitudes of the transmittance of silica glass in the middle of the lamp (block 11) and the transmittance of silica glass with sputtering (block 12) are obtained. After dividing the signal from block 12 to the signal from block 11 in block 13, the transmittance of the deposited film is deposited on the registering device 14, independent of the change in the transmission of quartz under the action of temperature.

The choice of the duration of the inclusion in the range from 3 s to 2.5 min and the cooling time of the lamp to 20-30 ° C is determined by the dependence of the transmittance change of the sprayed film in one inclusion on the duration of the inclusion (Fig. 2). The dependence obtained shows that for very short switching cycles (from one to several hundred half-cycles of the network frequency), the magnitude of the change in the transmittance is small. It quickly increases and reaches a maximum at 1.5 minutes of activation. A further increase in the duration of switching cycles leads to heating of the burner walls and cleaning of the walls due to evaporation of the deposited layer of electrode materials into the burner volume. Thus, with longer switching cycles (> 2.5 min), the data on the sputtering of the electrodes are underestimated due to the departure of a part of the deposited film into the volume. In addition, the test duration increases. An increase in the temperature of the burner walls above 20–30 ° C due to a reduction in the pause duration also leads to less deposition of the sprayed substance on the burner walls, as it decreases 5

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The temperature gradient is set upon subsequent power up.

The application of the proposed method and device for testing electrodes RGRL VD in comparison with the known reduces the testing time by reducing the duration of switching cycles and the independence of data from the anti-temperature effect on quartz glass. The method allows to assess the resistance of the RGRL VD electrodes to sputtering after 5 inclusions, which takes about 35 minutes of testing; if you increase the cooling efficiency of the burner, the test time is reduced to 7-10 minutes. When testing 15 by a known method, the elapsed time is approximately 70 hours. Time saving

Neither test provides energy savings.

Claims (1)

Non-destructive testing method electrodes of mercury high-pressure discharge lamps, consisting in the measurement of their luminous flux in the mode of cyclic inclusions and comparison with the luminous flux of the reference lamp, characterized in that. that, in order to reduce the time of testing and increase the efficiency of the method, the cycles of switching on the alternating current circuit are set in a time interval of 3 seconds - 2.5 minutes, and the cooling time is determined by the lamp walls reaching 20-30 ° C, Fi g / 1660069 Φίΐ2.2