Основы светотехники на английском языке, страница 8

A luxmeter and a power meterare required to conduct this experiment. Use the mains switch for switching on/off the unit.Experiment:•Screw the incandescent arc lamp into the socket provided.•Set up the circuit as shown in figure 2.3.1.1.distribution fieldNL1Q1E1Figure 2.3.1.1 Experiments setup•Measure the consumed electrical power Pel. of the lamp with the power meter.EVPel . = W•Measure the illuminance E of the incandescent arc lamp with aluxmeter.

The illuminance is made up of five different measuredvalues according to figure 2.3.1.2. The respective measuring distance away from the lamp is r = 0.5 m.E=•EV + E H 1 + E H 2 + E H 3 + E H 4= lx5Now use the illuminance to calculate the light current Φ of thelamp. Five sixth of the circumference of a sphere is assumed asan illuminated area.E=ΦAŸΦ = E⋅AwithΦ = E ⋅ A = lmA = 56 ⋅ 4 ⋅π ⋅ r 2EH2EH1EH4EH3Figure 2.3.1.2 Measuring of theilluminance EExperiments with the ILLUMINATION BOARDCharacteristic Values of an Incandescent Arc Lamp•Then calculate the luminous efficiency η of the incondescent arc lamp with the light current.η=•ΦPel .= lmWDetermine the luminous intensity Ι of the lamp at a solid angle of Ω = 10.47 sr (5/6 sphere).I=•35Φ= cdΩCalculate the quantity of light Q for a life of t = 5000 h.Q = Φ ⋅ t = Mlmh•Transfer all the values to the table 2.3.1.Pel.

/ WTable 2.3.1E / lxA/m2Φ / lmη/mxW-1Ι / cdQ / Mlmh36Experiments with the ILLUMINATION BOARDCharacteristic Values of an Incandescent Arc Lamp2.3.2Illuminance dependent on the warm-up timeTask:Record the characteristic E = f (t) of the illuminance dependent on the warm-up time t. A luxmeter and aclock (a stop watch is even better) are required to conduct the experiment.

Use the mains switch forswitching on/off the unit.Experiment:•Screw the incandescentarc lamp into the socketprovided.N•Set up the circuit shownin figure 2.3.2.1.L1•Measure the illuminanceevery 30 seconds at adistance of 0.5 m vertically above the lamp.•Enter the values in thetable 2.3.2.•Draw the characteristic inthe diagram provided infigure 2.3.2.2 using thevalues from the table.0t / min0.5distribution fieldQ1E1Figure 2.3.2.1 Experiments setup11.5232.53.544.55 … 10E / lxTable 2.3.2t / min900800700600500E / lx400300200100001234Figure 2.3.2.2 Illuminance of an incandescent arc lamp5678910Experiments with the ILLUMINATION BOARDCharacteristic Values of an Incandescent Arc LampEvaluation:Question: What can be said about the characteristic curve for the illuminance?Answer:3738Experiments with the ILLUMINATION BOARDCharacteristic Values of a Compact Fluorescent Lamp2.4Characteristic Values of a Compact Fluorescent LampTask:Determine the characteristic values electrical power, illuminance, light current, luminous efficiency, luminous intensity, quantity of light and phase angle cos ϕ of the compact fluorescent lamp used here.

A luxmeter and a power meter or cos-ϕ measuring instrument are required to conduct this experiment. Boththe power and the phase angle can be measured with the Universal Power Meter (Type 1091). If only apower meter or a cos-ϕ measuring instrument is available, the one variable must be used to calculate theother. Use the mains switch for switching on/off the unit.Experiment:•Screw the compact fluorescent lamp into the socket provided.•Set up the circuit as shown in figure 2.4.1.distribution fieldNL1Q1E1Figure 2.4.1 Experiments setup•Switch on the lamp and wait for it to warm up for about 3 minutes before you start the measurements.This is how long it takes for the compact fluorescent lamp to light with full intensity.•Measure the consumed electrical power Pel.

of the lamp with a power meter.Pel . = W•Measure the phase angle of the lamp with a cos-ϕ measuring instrument.cos ϕ = •EH1Measure the illuminance E of the lamp with a luxmeter. The illuminanceis made up of seven different measured values according to figure 2.4.2.The respective measuring distance away from the lamp is r = 0.5 m.E=EV + E H 1 + E H 2 + E H 3 + E H 4 + E H 5 + E H 67E = lxEH2EH6EH5EVEH3EH4Figure 2.4.2 Measuring of theilluminance EExperiments with the ILLUMINATION BOARDCharacteristic Values of a Compact Fluorescent Lamp•39Then use the illuminance to calculate the light current Φ of the lamp.

Five sixth of the circumferenceof a sphere is assumed as an illuminated area.E=ΦAŸΦ = E⋅AwithA = 5 6 ⋅ 4 ⋅π ⋅ r 2Φ = E ⋅ A = lm•Then calculate the luminous efficiency η of the compact fluorescent lamp from the light current.η=•Pel .= lmWDetermine the luminous intensity Ι of the lamp at a solid angle of Ω = 10.47 sr (5/6 sphere).I=•ΦΦ= cdΩCalculate the quantity of light Q for a life of t = 10000 h.Q = Φ ⋅ t = Mlmh•Transfer all the values to the table 2.4.Pel. / Wcos ϕE / lxA/m2Φ / lmη/mxWTable 2.4Evaluation:Question: How does the illuminance behave directly after switching on?Answer:-1Ι / cdQ / Mlmh40Experiments with the ILLUMINATION BOARDCharacteristic Values of a Fluorescent Lamp2.5Characteristic Values of a Fluorescent Lamp2.5.1Time for starting and ignition processTask:Start or ignite the fluorescent lamp with the electronic gear (EG) and with the mechanical and electronicstarter.

Determine, for example with a stop watch, the respective turn-on time or the time until the start orignition process ends. Use the mains switch for switching on/off the unit.Experiment:•Plug the fluorescent lamp into the socket provided.•Insert the mechanical starter in the socket provided.•Set up the circuit as shown in figure 2.5.1.1.distribution fieldNL1E1Q1Figure 2.5.1.1 Experiments setup: Ignition with mechanical and electronic starter•Measure the time until the Ignition process ends and the lamp lights without flickering. Note down thetime in the table 2.5.1.•Repeat the experiment with the electronic starter.•Set up the circuit as shown in figure 2.5.1.2 with the electronic gear.•Measure the time until the start process ends and the lamp lights without flickering.

Note down thetime in the table 2.5.1.Timet/sTable 2.5.1Mechanical starterElectronic starterElectronic gear (EG)Experiments with the ILLUMINATION BOARDCharacteristic Values of a Fluorescent Lamp41distribution fieldPENL1E1L1 N PEQ11EGFigure 2.5.1.2 Experiments setup: Starting with an electronic gear (EG)Evaluation:Question 1: What effect does the choke in figure 2.5.1.1 have?Answer:Question 2: What can be said about the turn-on time of the starters and the EG?Answer:42Experiments with the ILLUMINATION BOARDCharacteristic Values of a Fluorescent Lamp2.5.2Illuminance in operation with starter and electronic gearTask:Measure the electrical power Pel. and the illuminance E of the fluorescent lamp with the electronic starterand the electronic gear.

A power meter and a luxmeter are required to conduct this experiment. Use themains switch for switching on/off the unit.Experiment:•Plug the fluorescent lamp into the socketprovided.•Insert the electronic starter in the socketprovided.•Set up the circuit as shown in figure2.5.2.1.•Measure the consumed electrical power Pel.of the lamp with a power meter.Pel . starter = W•L1E1Q1Figure 2.5.2.1 Experiments setup with starterMeasure the illuminance E of the lamp witha luxmeter.

The measuring distance awayfrom the lamp is 0.5 m in vertical direction.Estarter = lx•distribution fieldNSet up the circuit as shown in figure 2.5.2.2with the electronic gear and repeat themeasurement.Pel . EG = WE EG = lxdistribution fieldPENL1E1Q1L1 N PE1EGFigure 2.5.2.2 Experiments setup with EGEvaluation:Question: Why is the illuminance greater in operation with an electronic gear than in operation with aconventional starter, despite greater brightness?Answer:Experiments with the ILLUMINATION BOARDCharacteristic Values of a Fluorescent Lamp2.5.343Illuminance under different ambient influencesTask:Measure the illuminance E of the fluorescent lamp under normal conditions and when a sheet of whitepaper is placed beneath the lamp.

A luxmeter is required to conduct this experiment. Use the mainsswitch for switching on/off the unit.Experiment:•Plug the fluorescent lamp into the socketprovided.•Set up the circuit as shown in figure 2.5.3.•Measure the illuminance E of the lampwith a luxmeter under normal conditions.The measuring distance away from thelamp is 0.5 m in vertical direction.E normal = lx•Place a sheet of white paper underneaththe lamp and repeat the measurement.E paper = lxdistribution fieldPENL1E1L1 N PEQ11EGFigure 2.5.3 Experiments setup with an EGEvaluation:Question: Why is the illuminance much greater when a sheet of white paper is placed underneath thelamp than under normal conditions?Answer:44Experiments with the ILLUMINATION BOARDCharacteristic Values of a Fluorescent Lamp2.5.4Power ratios in operation with starterTask:Examine the power ratios of a fluorescent lamp in operation with an electronic starter.

Determine thepower of the choke and the lamp. A power meter is required to conduct this experiment. Use the mainsswitch for switching on/off the unit.Experiment:•Plug the fluorescent lamp into the socket provided.•Insert the electronic starter in the socket provided.•Set up the circuit shown in figure 2.5.4.1.•Measure the consumed total electrical powerwith a power meter.Ptotal = W•L1E1Q1Figure 2.5.4.1 Measuring of the total powerThen measure the electrical power of thechoke. To do this, set up the circuit shown infigure 2.5.4.2.Pchoke = W•distribution fieldNdistribution fieldNL1Calculate the power of the fluorescent lamp.E1Plamp = WQ1Figure 2.5.4.2 Measuring of the choke powerExperiments with the ILLUMINATION BOARDCharacteristic Values of a Fluorescent Lamp2.5.545Dimming a fluorescent lampTask:Dim the fluorescent lamp with the potentiometer of the electronic gear.