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ISR300 Single Monochromator

  • ISR300 integrated monochromator
  • ISR300 with integrated picoammeter and HV supply

Built around a 300mm focal length, triple-grating turret Czerny-Turner monochromator, the ISR300 has two exit ports, selected by a solenoid-based swing away mirror, allowing the specification of up to two system detectors. Grating drive control electronics are located to the base of the unit alongside the signal recovery electronics, including dual-channel picoammeters and a high voltage power supply for operation of detectors in the photoemissive or photoconductive modes.

The ISR300 is a single unit with a lot of talents, ready for deployment in a number of applications.

Core benefits


  • 300mm focal length monochromator in Czerny-Turner mount
  • Triple grating turret
  • One entrance and two exit ports, all motorised with automated mirror-based selection
  • Integrated drive electronics, dual-channel picoammeter and high voltage power supply
  • Compatible with the full range of sources, detectors and accessories of the Bentham portfolio
  • Fully automated through USB 2.0 interface

Optical Layout

ConfigurationSymmetrical Czerny Turner
Focal length300mm
Grating mountTriple grating turret
Number of gratings1-3
Grating size68 x 84mm
Aperture ratiof/4.1 (at all grating angles)
Number of entrance/ exit ports1/2 or 2/1


Mechanical resolution drive0.00072°/ step
Slit typeInternal motorised variable
Slit width & height10µm-10mm (W) x 20 (H)
Filter size6-position filter wheel
Filter diameter25mm (see separate Order Sorting Filter datasheet for full range)

Optical Performance (quoted for 1200 g/mm gratings)

Spectral rangeWithin range 200nm-50µm
Linear dispersion2.7nm/mm
Wavelength accuracy± 0.2nm
Wavelength reproducibility± 0.05nm
Resolution full/reduced slit height0.3/0.1nm
Stray light rejection at 2.5 FWHM10-5
Wavelength acquisition speed1000nm/s


Computer interfaceUSB 2.0
Software controlBenWin+/SDK

Electrical/ Mechanical

Overall dimensions328L x 375W x 263H mm
Optical height178mm
WeightApprox. 15kg
Power supplyMains input 110/220V 50/60Hz


Diffraction gratingsSee Configurations Tab
Order sorting filtersSee Configurations Tab
Filter wheel252-6 (6-position filter wheel, includes shutter)

487 Dual-Channel Picoammeter Module - Electrical

Channel 1 inputCurrent input to picoammeter
Channel 2 inputCurrent input to picoammeter
Gain ranges1010-105 V/A
Maximum current input100µA
Frequency responseDC to 30Hz
Gain accuracy+1%
Gain stability200ppm/°C
Output stability5ppm/°C to 500ppm/°C depending on sensitivity
Linearity< 0.025% departure from linearity from zero to full scale
ADC resolution4½ digit BCD (0 to 19999) i.e. > 14 bit resolution
ADC integration time100ms
Auxiliary input range0- 9.8V
Picoammeter input impedanceVirtual earth
Auxiliary input impedance1 MΩ

415 High voltage Power Supply Module - Electrical

Output voltage range-350 to -1500V
Maximum current1.5mA
Temperature stability100 ppm/°C
Stability to voltage fluctuations25ppm for 10% change in line voltage
Ripple and noise100ppm peak-peak

Monochromator Configurations

ISR300 Configuration A 
ISR300 Configuration B 

Diffraction Gratings

Where a system is to be used over an exceptionally wide spectral range, requiring more than 3 diffraction gratings, interchangeable turrets are employed; the stepping motor in this case drives a platform to which the grating assembly is attached.

GratingLine density (g/mm)Grating type & Blaze wavelengthMaximum wavelength range
GA-T324R0U252400Plane ruled, 250nm blaze200nm-600nm
GA-T324H0U252400Plane holographic, 250nm blaze200nm-600nm
GA-T324H0U32400Plane ruled, 300nm blaze200nm-600nm
GA-T318H0U251800Plane holographic, 250nm blaze250nm-900nm
GA-T318R0U41800Plane ruled, 400nm blaze250nm-900nm
GA-T318R0U51800Plane ruled, 500nm blaze250nm-900nm
GA-T312H0U251200Plane holographic, 250nm blaze300nm-1.2µm
GA-T312R0U41200Plane ruled, 400nm blaze300nm-1.2µm
GA-T312R0U51200Plane ruled, 500nm blaze300nm-1.2µm
GA-T312R0U751200Plane ruled, 750nm blaze300nm-1.2µm
GA-T312R0U91200Plane ruled, 900nm blaze300nm-1.2µm
GA-T312R1U01200Plane ruled, 1µm blaze300nm-1.2µm
GA-T3083R1U2830Plane ruled, 1.2µm blaze600nm-1.8µm
GA-T306R1U0600Plane ruled, 1µm blaze800nm-2.5µm
GA-T306R1U25600Plane ruled, 1.25µm blaze800nm-2.5µm
GA-T306R1U6600Plane ruled, 1.6µm blaze800nm-2.5µm
GA-T306R1U9600Plane ruled, 1.9µm blaze800nm-2.5µm
GA-T306R2U16600Plane ruled, 2.16µm blaze800nm-2.5µm
GA-T304R1U6400Plane ruled, 1.6µm blaze1µm-3µm
GA-T303R3U0300Plane ruled, 3µm blaze1.5µm-5.5µm
GA-T303R4U0300Plane ruled, 4µm blaze1.5µm-5.5µm
GA-T3015R4U0-AU150Plane ruled, 4µm blaze. Gold coated.3µm-10µm
GA-T3015R6U0-AU150Plane ruled, 6µm blaze. Gold coated.3µm-10µm
GA-T301R9U0-AU100Plane ruled, 9µm blaze. Gold coated.4.5µm-16µm
GA-T30075R10U0-AU75Plane ruled, 10µm blaze. Gold coated.6µm-20µm
GA-T30075R12U0-AU75Plane ruled, 12µm blaze. Gold coated.6µm-20µm
GA-T3005R18U0-AU50Plane ruled, 18µm blaze. Gold coated.9µm-30µm
GA-T3005R19U5-AU50Plane ruled, 19.5µm blaze. Gold coated.9µm-30µm


An order sorting filter wheel is located inside the entrance port of the monochromator, fitted with 6 filters selected for the spectral range of use.

When measuring below 400nm, no filters are required as the corresponding wavelength of the subsequent diffraction order is less than 200nm, which is naturally blocked by the atmosphere.

Spectral rangeRequired OS filter
<400 mNone
3.6-6 µmOS3600
6-10.5 µmOS6000
10.5-21 µmOS10500
> 21µmPlease consult.

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