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SCANNING MINI-CHROM
The Scanning Mini-Chrom monochromator (SMC) is designed to be driven by stepping or servocontrolled motors. No wavelength readout is provided. All models utilize a precision lead screw/sine bar mechanism to rotate the diffraction grating and sequentially position the selected wavelength(s) at the exit slit. Rotation of the drive shaft in a clockwise direction proportionately increases the wavelength of radiation at the exit slit. Scanning Mini-Chroms are used in applications requiring either single or repetitive scans of wavelength intervals or the sequential selection of discrete wavelengths. To prevent mechanical damage due to inadvertently exceeding wavelength limits, all Scanning Mini-Chroms are supplied with dual photosensors that function as high and low limit switches. Overall dimensions in mm: 95 x 59 x 49; Weight 0.45 Kg (1.0 lb).

ADDITIONAL SPECIFICATIONS
Drive Hysteresis. . . . . . . . . . 3.6 deg typ., 14 deg max.

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SCANNING DIGITAL MINI-CHROM
The Scanning Digital Mini-Chrom (SDMC) includes an integral stepping motor which can be controlled by a calibrated drive such as the PCM-01 via a 15-pin connector. The SDMC is similar to the Digital Mini-Chrom in that it includes a four digit counter for wavelength readout and a dial for manual wavelength selection. For near infrared models (05 and 06), the four digit counter reading must be doubled, to 2 nm per division, for wavelength selection and readout. Dual photosensors that function as high and low limit switches are included for use in the scanning model. The Scanning Digital Mini-Chrom can be used for all applications that require the convenience of a built-in wavelength readout as well as applications requiring scanning to a selected wavelength or over a wavelength interval. Overall dimensions in mm: 197 x 59 x 49; Weight 0.9 Kg (1.9 lbs).

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MODULES

SAMPLE COMPARTMENT
The versatile Optometrics Sample Compartment accepts standard 1 cm square cells or solid samples up to 50 x 50 x 10 mm. A quartz lens focuses incident radiation in the center of the cell or on the front surface of a solid sample depending on the position of the sample stage. Two additional quartz lenses focus transmitted, reflected or emitted radiation at the in-line or 90 degree detector ports. A filter holder, which accepts Optometrics' 25.4 mm diameter filters, is attached to the inside of each port.

When measuring the percent transmittance or absorbance of a solution or a transparent solid sample, the sample stage and detector are positioned in-line. Fluorescence or nephelometric measurements are made with the detector positioned 90 degrees to the incident radiation. Reflectance measurements from solid samples require rotating the sample stage 45 degrees and placing the detector 90 degrees to the incident radiation. Overall dimensions in mm: 218 x 168 x 92; Weight 2.5 Kg (5.4 lbs.)

For information on detectors that plug into the sample compartment contact Optometrics.

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SPECULAR REFLECTANCE ACCESSORY
The specular reflectance accessory mounted in the sample compartment is designed to measure the reflectance of solid samples such as mirrors, paint samples, etc. The reflectance accessory is pre-mounted in the Optometrics sample compartment, which aligns directly to the exit port of an Optometrics Mini-Chrom monochromator. Mono- chromatic light from the exit slit of the monochromator is reflected onto the sample, which is held in position by a spring-loaded mount. The angle of incidence at the sample is 11 degrees. Light from the sample is reflected to the exit port of the sample compartment. A detector is placed at the exit port to measure the amount and hence the reflectance from the sample.

The standard sample compartment can be used for samples requiring 45 degree reflectance measurements whereas the Specular Reflectance Accessory is designed for measurements requiring an 11 degree angle of incidence. Maximum sample size is 7 x 14 cm.

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STEPPING MOTOR CONTROLLER
The PCM-01 is a modular component, ideally suited for driving the Optometrics LLC line of Scanning Digital Monochromators.

Using a personal computer, the operator can move the monochromator to a specific wavelength and scan over a wavelength range. The PCM-01 application program can be used with Windows 95 or 98.

When a terminal is used to drive the monochromator, the user can access over 25 commands that control a variety of operations of the grating drive (e.g. including the distance to be moved, the initial and final velocities of the move, the acceleration, the time period for pauses, etc.). Commands can be sent at any time, even when the motor is operating. The motor controller board includes over 2,000 bytes of nonvolatile memory to store complex motion control programs.

Six different Scanning Digital Monochromators are available for use with the PCM-01. Each monochromator is fitted with a pair of entrance and exit slits specified by the user. Additional slits can be ordered separately.

Specifications

Motor Drive:
Type	-	Bi-polar
No. of phases	-	2
Step Modes	-	Full and half
Step Rate	-	16-23,000/second
Max Step Range	-	± 8,388,607 steps
Max Current	-	1.2 amps/phase
Voltage	-	24 vdc
Motor Leads	-	4,6 or 8
Communications:
Operating Mode	-	Single and party line
Interface	-	RS-232
Baud Rate	-	9600
Data Bits	-	8
Stop Bits	-	1
Parity	-	None
Flow Control	-	XON/XOFF
I/O Connections:
Limits	-	Limit A
	-	Limit B Moving
Go
Soft Stop
LogicCom
Memory:
Non-Volatile	-	2048 bytes

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A slide switch enables the selection of the time constant and “fast” for the recording (RS) spectrophotometer and computer data acquisition. Power to the modules ( ± 15V DC) can be supplied with a wall mounted power supply (for 115V AC) or by an external power supply (for 230V AC).

DETECTOR MODULES
Optometrics’ Silicon Detector Modules are designed for direct mounting on Mini-Chrom monochromators or in either aperture of the standard Sample Compartment. The modules are compact, low cost, simple to mount and require no user alignment. The silicon detectors have a wide spectral response (200 nm to 1100 nm) with a peak response at approximately 900 nm. The detectors cover the UV-VIS-NIR spectral region and are used extensively as components in analytical and biomedical instrumentation, and in research, teaching and quality control. In addition to their wide spectral response, photocells have excellent linearity and signal-to-noise ratios. The Detector Module consists of a mounted silicon photodiode, an integral low noise, high speed and exceptionally high stability operational amplifier and a slit assembly in a rugged housing. Mounting is facilitated by a pair of banana plugs on the slit assembly. When exposed to electromagnetic radiation of sufficient energy, photocells generate an electrical signal. The signal is the result of a photon induced difference in potential between the P and N layers within the photocell, i.e. the photovoltaic effect. The signal is proportional to the energy of the impinging radiation and varies as a function of wavelength. The Silicon Detector Module incorporates a photocell with low dark current, a fast response time, a quartz window and thin P-layer for an enhanced response to ultraviolet radiation.

Specifications

Detector Module with Silicon Photodiode:
Detector Type	-	UV enhanced Silicon
Spectral Range	-	200 nm to 1.1 µ
Peak Response	-	950 nm ± 50 nm
Photosensitive Area	-	5.9 mm sq.
Output Signal	-	0 to 14V DC full scale
“Slow” Time Constant	-	50mSec.
Cut-off Frequency	-	3 Hz
“Fast” Time Constant	-	10mSec.
Cut-off Frequency	-	15 KHz
Radiant Sensitivity (A/W):	-	0.1 @ 254 nm (Hg)
	-	0.38 @ 632.8 nm (HeNe)
	-	0.5 @ 930 nm (GaAs)

CATALOG NO.	7-1302	7-1303	7-1310
DETECTOR MODULES	Silicon photodiode with wall mounted power supply (115V AC TO ± 15 V DC)	Silicon photodiode with adapter cable for connection to a ± 15 V DC power supply	Silicon photodiode with wall mounted power supply (230V AC TO ± 15 V DC)
PRICE *	695.00	605.00	795.00

* Prices are in USD and are list prices only.

DETECTOR ACCESSORIES Slit assemblies for the Detectors when used with Mini-Chrom Monochromators
CATALOG NO.	7-1304	7-1305	7-1306	7-1307	7-1308	7-1309
SLIT SIZE	With 50 μ x 4 mm slit	With 100 μ x 4 mm slit	With 150 μ x 4 mm slit	With 300 μ x 4 mm slit	With 600 μ x 4 mm slit	With 1 mm x 4 mm slit
PRICE *	50.00	50.00	50.00	50.00	50.00	50.00

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