Digital Light Intensity Controller

The 68950 is a digital exposure system for research lamp sources. The system is a light intensity controller and digital timer in one. The light intensity controller maintains a constant light output from your arc, deuterium, or quartz tungsten halogen lamps, whereas the digital timer allows timed exposures and dose control. RS-232 communications allow computer controlled operation.

Light intensity controller and digital timer in one
Ensures stable long term output from arc, deuterium and QTH lamps
Dose control
RS-232 communications

See All Features

Description	Compatibility	Avail.	Price
44899 Digital Light Intensity Controller5° Wedged Substrate 1.0 inch diameter, Fused Silica	UNIVERSAL	Discontinued
68950 Digital Light Intensity ControllerDigital Exposure System, Research Lamp Sources	UNIVERSAL		$6,820
71594 Digital Light Intensity ControllerOptic Holder, Rod Mount, 1 inch	UNIVERSAL	Discontinued

Features

Correct for Lamp Output Variations with Age

Our lamp power supplies are highly regulated and operate lamps at constant current or power, even if the line voltage changes over a wide range. Even with lamp current constant, the light output of many lamps varies with age, filament or electrode erosion, gas adsorption or desorption, and, particularly for mercury lamps, ambient temperature. Both the total output and the distribution of power between the spectral lines from a mercury lamp change with temperature. These effects cause output variations with time, with different and sometimes pronounced frequency dependence. Even the relatively simple quartz tungsten halogen lamps exhibit output variations: evaporation and halogen cycle redeposition of tungsten constantly change the microstructure of the filament. The 68950 corrects for these lamp output changes, maintaining a constant, long term output, from the lamp.

Intensity of arc lamp under with and without 68950 control.

Ideal Optical Set-up

We recommend that you rod mount the light sensor as shown in Fig. 3, using a 5° Wedge to split off part of the beam. The normal surface reflection off the substrate is enough to "pick-off" a portion of the beam for monitoring by the 68950 sensor. You can also use a beamsplitter at 45°, but you may need to attenuate the light hitting the sensor with an aperture, diffuser or filter, depending upon the reflectance of the beamsplitter. The 7123 Mount holds a 1 inch (25.4 mm) diameter optic at the input of the light sensor. Another method of monitoring the light output, if you have plenty of light to spare, is to use an integrating sphere at the output of the source, and mount the light sensor on one of the sphere’s ports.

Monitors and Adjust Light Output

The 68950 is made up of a light sensing head and a controller. The silicon based light sensor is temperature stabilized to maintain complete independence from temperature variations and monitors part of the light source's output. The controller constantly compares the recorded signal to the set level and changes the power supply output as the lamp ages or as other conditions cause a change.

Built-in Digital Timer

The built-in digital timer controls any of our electronic shutters for timed exposure applications. Accurate, repeatable timed exposures down to 2 ms are possible. The Digital Exposure System for Research Sources, model 68950, doesn't directly drive the shutter, but rather provides a TTL output signal for the shutter controller, which is a part of the shutter system. We also offer Electronic Safety Shutters.

Adapter Kits for Oriel^® Lamp Housings

For convenience, you can mount the sensor directly to the lamp housing. The 68952 Adapter Kit mounts the sensor off our Research Housings, looking transversely at the lamp. The 68952 includes a filter holder with a beam attenuator. The 68954 Adapter Kit mounts the sensor on an unused port of the Series Q Housing. It also includes a filter holder and beam attenuator.

The 68952 Adapter Kit shown connecting a 71582 Silicon detector to a research lamp housing

Accessories

Compatible Lamp Housings

Description	Compatibility	Price
60000 Lamp Housing, Q Series, Adjustable Reflectors & Up to 4 Condensers	UNIVERSAL	$2,160
66881 QTH Lamp Housing, Research, 10-250 W, F/0.85 Borofloat Glass, Collimated	UNIVERSAL	$3,475
66885 QTH Lamp Housing, Research, 600-1000 W, F/1, 2 Element FS, Collimated	UNIVERSAL	$4,195
66901 Arc Lamp Housing, Research, 50-500 W, F/1.5 Plano-Convex, 1.5 Inch Flange	UNIVERSAL	$3,640
66902 Arc Lamp Housing, Research, 50-500 W, F/1 2 Element Plano-Convex, 1.5 Inch Flange	UNIVERSAL	$3,745
66921 Arc Lamp Housing, Research, 450-1000 W, F/1 2 Element Plano-Convex, 2 Inch Flange	UNIVERSAL	$5,740
66923 Arc Lamp Housing, Research, 450-1000 W, F/0.7, 4 Element Aspherab, 3 Inch Flange	UNIVERSAL	$9,885
67001 Arc Lamp Housing, Research, 50-500 W, F/2.2 Asphere, 1.5 Inch Flange	UNIVERSAL	$4,180
67005 Arc Lamp Housing, Research, 50-500 W, F/1 Asphere, 1.5 Inch Flange	UNIVERSAL	$4,245
67009 QTH Lamp Housing, Research, 10-250 W, F/2.2 FS Asphere, Collimated	UNIVERSAL	$4,255
67011 QTH Lamp Housing, Research, 10-250 W, F/1 FS Asphere, Collimated	UNIVERSAL	$4,215

Adapter Kits

	Compare	Description	Compatibility	Drawings, CAD & Specs	Avail.	Price
		68952 Adapter Kit, Research Lamp Housing to Light Intensity Controller/Timer	UNIVERSAL			$315
		68954 Adapter Kit, Q Series Lamp Housing to Light Intensity Controller/Timer	UNIVERSAL			$455

Resources

Manuals

Oriel 6895X Digital Exposure Systems User Manual(657.2 kB, PDF)

Digital Light Intensity Controller