Night vision Radiometer/Photometer/Colourimeter
          
            The
            NviSpot Night Vision Radiometer/Photometer/Colourimeter is a 
           multipurpose instrument designed to meet the NVIS radiance light 
           measurement compatibility requirements of MIL-L-85762 for NVIS 
           applications, and also perform the conventional fast and accurate 
           luminance and colourimetric light measurements long associated with 
           the PR-1500 SpotMeter 
          
           It consists of a modified 
           Pritchard-type filtered photometer system with interchangeable 
           objective lenses and an internal calibration source. For NVIS 
           measurements it includes a proprietary filtered, extended-red gallium 
           arsenide photomultiplier tube with overload protection, threshold 
           detection and an NVIS-compatible digital display readout. Although 
           the NVISpot does not replace the requirement for a laboratory-grade spectro-radiometer
            specified in the MIL Spec, it does provide a relatively inexpensive 
           and highly accurate means of light measurement for all phases of 
           production and control testing. 
          
           NVIS
            radiance mode 
          
           For the Aviators Night 
           Vision Imaging System (NVIS) applications, the PR-1530AR includes a 
           special filter/detector combination whose transmission curve 
           precisely matches the NVIS relative response in MIL-L-85762. 
          
           When operated in the NVIS 
           Mode, the NviSpot display reads out in NVIS Radiance (NRa or NRb) 
           units. Relative colourimetric filters are optionally available for 
           evaluating the colour of the device under test, i.e., Green A, Green 
           B, Yellow and Red. 
          
           The digital display of the 
           PR-1530ARis specifically NVIS-filtered to eliminate any inaccuracy 
           it's own light output might introduce into the test results. 
          
           A very useful feature in 
           the NVIS mode is the user adjustable threshold detection. An audible 
           tone is generated when the display reading exceeds the maximum value 
           of NR units set by the user for the device and/or test. This feature 
           enables the PR-1530AR to be used as a rapid GO/NO-GO test instrument 
           for on-line inspection of a series of devices that share a common NR 
           upper limit, for instance 1.7 x10-10 NR units. An optional fiber 
           optic probe, the LP-15, further enhances the GO/NO-GO testing feature. 
          
           The calibration accuracy 
           required by the MIL-L-85762 us assured through the inclusion of an 
           extremely stable internal reference standard. Correct calibration can 
           be instantly verified at any time without the need for any external 
           calibration sources or relying upon some vague factory calibration. 
           And to prevent the accidental damage to the sensitive photodetector, 
           a resettable automatic overload protection circuit has been designed 
           into the PR-1530AR. 
          
           Lens accessories are 
           available to modify the field coverage of the PR-1530AR over the 
           entire range of devices likely to be measured for NVIS requirements. 
           A uniquely shaped fiber optic probe, the LP-15, is available for 
           measurements best suited to its field coverage capabilities. Analog 
           output is included, and a BCD output is optionally available to 
           permit interfacing to a host computer or data-logger. 
          
           Luminance/Colourimeter
            modes 
          
           While the NviSpot is 
           designed primarily for measurements relating to MIL-L-85762, it also 
           functions as an extremely sensitive luminance and colourimetric 
           measuring instrument. In this mode it acts as a high performance PR-1500 
           SpotMeter. Many of the standard PR-1500 accessories can be used with 
           the NviSpot to extend its versatility to include the features 
           currently available with the PR-1500 SpotMeter. 
          
           Features 
          
           - 
           
            Direct NVIS(NRa, NRb) 
            measurements and GO/NO-GO testing of GreenA, GreenB, Yellow or Red 
            panels or filters 
              - Adjustable
             sensitivity threshold (NR) units with beeper
 
             - Stand-alone,
             high performance, photopically corrected Filter Photometer.
 
             - Resettable
             detector overload protection with beeper
 
             - Illuminance/Irradiance
             measurements(with optional accessories)
 
             - Relative 
            colorimetric measurements of NVIS devices (optional)
 
             - Capabilities
             of the PR-1500 SpotMeter
 
             - Internal 
            calibration source
 
             - NVIS 
            compatible readout
 
             - Wide 
            range of optical accessories
 
             - Dual 
            sensitivity ranges for optimum performance
           
  
          
           Specifications 
          
          
            
            
             | 
               
               Measuring
                field aperture  | 
             
               
               3 Degrees  | 
             
            
             | 
               
               Spot size*  | 
             
               
               3° to 
               0.003 inches. (0.016 inches with the 7X standard objective lens)(See Field
                Coverage and Relative Sensitivity table)  | 
             
            
             | 
               
               Spectral 
               response(NVIS filtered)  | 
             
               
               per 
               MIL-L-85762(450 nm to 930 nm) Consult factory for Class A, Class B or both  | 
             
            
             | 
               
               Spectral response(photopic)  | 
             
               
               380 nm to 
               760 nm  | 
             
            
             | 
               
               Photometric
                Accuracy  | 
             
               
               ±5% of 
               full scale or ±1 digit (whichever is greater)  | 
             
            
             | 
               
               Readout  | 
             
               
               3½ 
               digits green LED display (filtered for NVIS compatibility)  | 
             
            
             | 
               
               Output signals  | 
             
               
               0-2 volts 
               analog standard; BCD parallel optional  | 
             
            
             | 
               
               Sensitivity  | 
             
               
               10-4 
               to 104 
               footLamberts, 10-11 
               to 10-3 
               NR units.  | 
             
            
             | 
               
               Power  | 
             
               
               117±13volts,
                50 to 400Hz, 5 watts max(230±40volts available on request)  | 
             
            
             | 
               
               Size  | 
             
               
               12½ 
               inches(31.3 cm) x 6¼ inches(15.9 cm) high x 5¾ inches(14.6 cm)  | 
             
            
             | 
               
               Weight  | 
             
               
               8½ 
               pounds(3.6 Kg.)  | 
             
            
          
          
           Field
            Coverage and Relative Sensitivity  
          
          
            
            
             | 
               
               Lens/*Optical
                Accessory  | 
             
               
               Lens-to-subject
                distance  | 
             
               
               Nominal 
               Field Coverage  | 
             
               
               Relative**
                Sensitivity Multiplier  | 
             
            
             | 
               
               MS-75 (1X)  | 
             
               
               1.75 in. 
               (44.5 mm) 
               to infinity  | 
             
               
               0.114 in. 
               (2.90 mm) 
               (at 1.75 in.)  | 
             
               
               1.  | 
             
            
             | 
               
               MS-1X  | 
             
               
               3.8 in. 
               (96.5 mm)  | 
             
               
               0.114 in. 
               (2.90 mm)  | 
             
               
               1.  | 
             
            
             | 
               
               MS-2.5X  | 
             
               
               1.76 in. 
               (44.7 mm)  | 
             
               
               0.046 in. 
               (1.17 mm)  | 
             
               
               1.  | 
             
            
             | 
               
               MS-77(3X)  | 
             
               
               4.1 in. 
               (104 mm)  | 
             
               
               0.038 in. 
               (0.97 mm)  | 
             
               
               1.  | 
             
            
             | 
               
               MS-5X  | 
             
               
               1.11 in. 
               (28.2 mm)  | 
             
               
               0.023 in. 
               (0.58 mm)  | 
             
               
               1.  | 
             
            
             | 
               
               MS-7X 
               (Standard Objective)  | 
             
               
               0.7 in. 
               (17.8 mm)  | 
             
               
               0.016 in. 
               (0.41 mm)  | 
             
               
               1.  | 
             
            
             | 
               
               MS-10X  | 
             
               
               0.61 in. 
               (15.5 mm)  | 
             
               
               0.011 in. 
               (0.28 mm)  | 
             
               
               10.  | 
             
            
             | 
               
               MS-25X  | 
             
               
               0.6 in. 
               (15.24 mm)  | 
             
               
               0.0045 in. 
               (0.114 mm)  | 
             
               
               100.  | 
             
            
             | 
               
               MS-50X  | 
             
               
               0.6 in.  | 
             
               
               0.0023 in. 
               (0.058 mm)  | 
             
               
               100.  | 
             
            
             | 
               
               LP-15  | 
             
               
               Contact  | 
             
               
               0.015 x 
               0.090 in. 
               (0.38 x 
               2.29 mm)  | 
             
               
               10.  | 
             
            
          
          
           *All lenses 
           are fixed focus except the MS-55 lens. Contact factory for lenses of 
           other field coverages. 
          
           **A 
           relative sensitivity multiplier of 10 means the PR-1530AR is 1/10 as 
           sensitive with the accessory as with the MS-55 lens 
          
              |