C995 Optical Chopper
Features:● Large 5 Digit LED Display● Frequency resolution of 0.001 Hz● External Clock Synchronization● Covers 4 Hz to 5 KHz with only one blade● Computer Interface for easy control● Enclosed Chopper BladeT

4Hz to 5KHz Optical Chopper

he C-995 is a microprocessor-based control system that utilizes direct-digital-synthesis to deliver precise opticalchopping 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. Additionally, the C-995 is equipped with a bidirectional
Rs-232 port that permits the user to set the desired chopping rate to a resolution of .001 Hz and to read the statusof the instrument.
The C-995, designed with a phase-locked-loop control system, allows the chopping rate to also be synchronized toa user-supplied external clock ranging from 4 Hz to 5 KHz. The controller is then used to measure and display thefrequency of the external clock.
The C-995 chopping head is attached to the controller by means of a 10 foot coiled cord. The precision etchedblade is fully enclosed for protection from inadvertent damage. (An optional open blade version is also available.)
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 convenience 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 andour guarantee of customer satisfaction.

Terahertz Technologies Inc.

Made In the USA

169 Clear Rd., Oriskany NY 13424
Toll Free: 888-U.S.- OTDRS
Phone: 315-736-3642 Fax: 315-736-4078
E-mail: sales@teratec.us
Web: www.teratec.us

C995 Optical Chopper
Specifications
Chopping Frequency Range

4 Hz to 500 Hz ( Inner slots), 40 Hz - 5 KHz (outer slots)

Aperture Size

0.6 inch diameter (15 mm), and 0.6 inch by 0.2 inch (15 x 4.5 mm)

Frequency Control

Phase-Locked-Loop, Direct Digital Synthesis

Frequency Uncertainty±.0025 % of setting

Phase Jitter (Internal Operation Only)

0.1 % peak to peak, 3 slot section, 1.0 % peak to peak, 30 slot section

Settling Time to Phase Lock

< 3 seconds

External Clock Input Requirements

TTL, CMOS Compatible Square Wave, 4 Hz to 5000 Hz

Sync Signal Output

TTL, CMOS Compatible Square Wave

Display

Five Digit, high intensity green, 0. 5 “ highTemp. Coefficient of Chopping Frequency< 10 ppm/CFrequency Resolution (W/Rs-232 Control).001 Hz

Frequency Resolution (W/Front Panel Control).01 HzCounter Resolution using External Clock

0.1 Hz, 1 Hz

Rs-232 Interface

9600 Baud, N-8-1, 3 wire

Chopper Head MountingStandard 8-32 tapped holes, mounting rod and stand is provided

Chopper Blade Diameter4.1 inch diameter

Operating Temperature Range

0 - 40 C

Dimensions (Head)

4.5 “ H x 4.5 “ W x 2 “ D, 114 mm x 114 mm x 51 mm

Dimensions (Controller)

2.7 “ H x 7 “ W x 9.1 “ D, 69 mm, 178 mm, 231 mm

Interconnecting cable supplied

Coiled Cord 10 feet max length

Power Requirements

95-260 VAC, 50-60 Hz, 15 VA Max

CE Certification

Yes

Weight3 lbs, 1.36 Kg

Accessories Provided

Mounting rod and stand, Rs-232 cable, Power Cord, Operating Manual

Standard Warranty

Two years, Components and Workmanship, 30 Day Satisfaction Guarantee

Application Software Provided

Downloadable from TTI website, www.teratec.us

Part Numbers
C-995

4 Hz to 5KHz Optical Chopper with Closed Head (5/8” Apeture) and 3/30 Slot BladeC-995-OH

4 Hz to 5KHz Optical Chopper with Open Chopper Head and 3/30 Slot BladeC-995-3

4 Hz to 500Hz Optical Chopper with Closed Head (1” Aperture) and 3 Slot BladeC-995-OH-3

4 Hz to 500Hz Optical Chopper with Open Chopper Head and 3 Slot BladeC-995 -Blade

3/30 Slot BladeC-995 -Blade-3S

3 Slot Blade

Made In the USA

TTI makes every effort to insure all statements and information for the products referred to in this document are accurate and reliable. TTI can not accept any responsibility forerrors, omissions or miss statements, nor can they accept
responsibility for any actions taken based on the information demonstrated herein. TTI reserves the right to makechanges of any kind to the product referred to in this document without prior notice.
© 12/2017 Terahertz Technologies Inc.