C-995 Variable Speed Microprocessor Controlled Optical Chopper Benefits: • Wide Frequency Range • Single Blade 4 Hz - 5 KHz • Crystal Controlled Stability • External Clock Synchronization • Enclosed Blade • Frequency Resolution 1mHz • Bright 5 Digit LED Display • Adjustable Aperture Height • Bidirectional Rs-232 Port The C-995 is a microprocessor-based control system that utilizes direct-digital-synthesis to deliver precise optical chopping rates from 4 Hz to 5000 Hz. Equipped with a large five-digit LED readout, the C-995 controller enables digital entry of the desired chopping rates from the front panel. Additionallly, the C-995 is equipped with a bi-directional Rs-232 port that permits the user to set the desired chopping rate to a resolution of .001 Hz and to read the status of the instrument. The C-995, designed with a phase-locked-loop control system, allows the chopping rate to also be synchronized to a user-supplied external clock ranging from 4 Hz to 5 KHz. The controller is then used to read the frequency of the external clock. The C-995 chopping head is attached to the controller by means of a 10 foot coiled cord. The precision etched blade is fully enclosed for protection from inadver tent damage. There are two apertures and two sections (30 slots and 3 slots)for the high and low frequency ranges, respectively. The aperture diameter is 15 mm with a slot width of 4.5 mm (30 slot section) or 30 mm (3 slot section). The small 4.75 inch square outline and two inch maximum depth permits easy integration into compact optical setups. Dual #8-32 mounting holes permit the apertures to be placed at a height as low as 0.75 inches above an optical bench, or with the included 1/2 inch rod and stand, as high as 13 inches above the mounting surface The ease of use and convience of this instrument are matched only by the high performance to price ratio that is typical of products from Terahertz Technologies Inc. The C-995 is backed by our standard two year warranty and our guarantee of customer satisfaction.

TTI reserves the right to change specifications w/o notice Chopper Heads Enclosed Blade Open Blade Scitec Instruments Ltd Bartles Industrial Estate North Street Redruth Cornwall TR15 1HR United Kingdom Tel: +44 (0)1209 314 608 Fax: +44 (0)1209 314 609 Fax: +44 (0)870 1600 860 www.scitec.uk.com [email protected]