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C-995 Optical Chopper

Update: 2019/10/12      View:
  • Brand:    eachwave
  • Type:    C-995
  • Order Online
    The C-995 Optical Chopper is a microprocessor-based control system that utilizes direct-digital-synthesis to deliver precise optical chopping rates from 4 Hz to 5000 Hz. The C995 Optical Chopper is 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, this Chopper 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 Chopper is 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 measure and display the frequency of the external clock. 

    The C-995 optical 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 inadvertent damage. (An optional exposed  or open head version is also available.)

    There are two apertureson the chopper head and two sections (30 slots and 3 slots) on the blade for the high and 
low frequency ranges, respectively. The aperture diameter is 15 mm with a slot width of 4.5 mm for the 30 slot section and 30 mm for 3 slot section. The small 4.75 inch square outline and two inch maximum depth of the chopper head 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 and our guarantee of customer satisfaction.


Wide Frequency Range 4 Hz to 5000 Hz
Rock Solid Crystal Controlled Frequency
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 Blade

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

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


Five Digit, high intensity green, 0. 5 “ high

Temp. Coefficient of Chopping Frequency

< 10 ppm/C

Frequency Resolution (W/Rs-232 Control)

.001 Hz

Frequency Resolution (W/Front Panel Control)

.01 Hz

Counter Resolution using External Clock

0.1 Hz, 1 Hz

Rs-232 Interface

9600 Baud, N-8-1, 3 wire

Chopper Head Mounting

Standard 8-32 tapped holes, mounting rod and stand is provided

Chopper Blade Diameter

4.1 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



3 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

Eachwave Scientific Instrument Co., LTD
Add: 3F-302,Focus Innovation Park,Yuanjiang Road No.3599,Minhang District,Shanghai  P.R.C (201108)
Tel: 021-62209657
Fax: 021-54843093

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