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Photo
Research spotmeters are the standard of the industry.
 Over
four decades ago, PhotoResearch invented "spot" photometry
when it introduced the Spectra Screen Brightness Meter for the motion
picture industry. A few years later, a military customer inquired
about measuring aircraft instrument panels and Photo Research
produced the first Spectra Spotmeter microphotometer
The PR-1500 Spotmeter is a
sensitive, versatile photomultiplier-tube photometer that can measure
luminance (photometric brightness) at any distance from 1¾
inches (44 mm) to infinity without the need for accessory lenses or
changes in calibration. The PR-1600 SpectraSpot, a silicon-cell
photometer/radio meter, is designed for applications requiring the
inherent stability and near infrared response of the silicon cell,
without requiring the higher sensitivity of photo multiplier tubes.
Typical
applications
-
Display measurements
- Cathode
ray tube luminance
- MIL-SPEC
Lighting compliance
- Street
and Roadway lighting
- Aircraft
Panel Checkout
- Material
Reflectance Studies
- Automotive
Lighting
- Colour
Temperature Determination
- Airport
lighting
- Air
pollution monitoring
- Lamp
quantity control
Photomultiplier
tubes
The standard
photomultiplier phototube supplied has an S-20 response. These are
specially selected and seasoned low-noise photodetectors.
Filter
Turret
A 6-position filter turret
is located the aperture mirror and the photomultiplier detector. This
turret contains the "photopic" filter which modifies the
spectral response of the instrument to precisely match CIE or
"human eye" response. This photopic filter is individual
trimmed and calibrated for each SpotMeter. With this filter in
position the Spot meter functions as a precision luminance
photometer(photometric brightness meter).
Red and blue filters are
included in standard instruments for relative tristimulus and colour
temperature measurements. (If special filters, such as red LED or
scotopic response filters are installed, tristimulus and/or colour
temperature measurements capability is not available) Option 32
provides three individually trimmed colourimetric filters for red,
blue and photopic making the PR-1500 a more accurate relative
colourimeter. The filter turret has an OPEN position for use in
making relative radiometric measurements. An internal
calibration-reference source is mounted in the CAL position of the
turret for quickly checking the instrument calibration prior to
making a measurement.
PR-1500
SpotMeter Lens Selection and Field Coverage Chart
|
Objective
Lens |
Focusing Range |
Working Distance |
Aperture Size |
|
3° |
1° |
½° |
¼° |
1/8° |
½°
x 1½° |
1/8° x 1½° |
|
MS-55* |
1.75 in. to infinity
(45 mm to infinity) |
10 ft.
(3.05 m) |
6.30 in.
(160 mm) |
2.10 in.
(53.3 mm) |
1.05 in.
(26.7 mm) |
0.53 in.
(13.5mm) |
0.26in.
(6.6 mm) |
1.05 in. x
3.15 in.
(26.7 mm x
80 mm) |
0.26 in.
x 3.15 in.
(6.6 mm x
80 mm) |
|
MS-1X |
FIXED |
3.80 in.
(96.5 mm) |
0.114 in.
(2.90 mm) |
0.038 in.
( mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-165 |
FIXED |
6.5 in.
(165 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-2.5X |
FIXED |
1.76 in.
(44.7mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-77 |
FIXED |
4.25 in.
(108 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-5X |
FIXED |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-7X |
FIXED |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-10X |
FIXED |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-25X |
FIXED |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-50X |
FIXED |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-55
with 12mm extension |
FIXED |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-55
with 36mm extension |
FIXED |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
MS-55
with 68mm extension |
FIXED |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
WL-15 |
6.6 in. to infinity |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
|
ZL-15 75-205mm |
78 in.
to infinity |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
10 in.
(3.05 mm) |
Full-Scale
Sensitivity Chart
|
Accessory |
Units |
Aperture |
|
1° |
½° |
|
MS-55
MS-1X
MS-165
MS-2.5X
MS-77
MS-5X
MS-7X
MS-10X
WL-16
ZL-16 |
footLamberts
= fL
Option 52-0 |
10-2
to 10+2 |
10-1
to 10+3 |
|
microwatts
per steradian/square centimeter
mw.sr-1.cm-2
Option 52-0 |
10-2
to 10+2 |
10-1
to 2x10+3 |
|
candelas
per square meter
cd.m-2
Options 52-1 |
10-1
to 10+3 |
100
to 10+4 |
|
mw.sr-1.cm-2
Option 52-1 |
10-1
to 10+3 |
100
to 10+4 |
|
MS-25X
MS-50X
FP-16 |
fL |
10-1
to 10+3 |
100
to 10+4 |
|
mw.sr-1.cm-2
Option 52-0 |
100
to 10+4 |
10+1
to 2x10+5 |
|
cd.m-2 |
100
to 10+4 |
10+1
to 10+5 |
|
mw.sr-1.cm-2 |
10+1
to 10+5 |
10+2
to 10+6 |
|
CR-100 |
footcandles
= fc-Opt.52-0
(lux = lx-Opt.52-1) |
10-1
to 10+3
(10+1
to 10+5) |
100
to 10+4
(10+2
to 10+6) |
|
IB-16 |
fc
(lx) |
10-6
to 10-2
(10-4
to 100) |
10-5
to 10-1
(10-3
to 10+1) |
|
LR-16 |
millicandelas
- Opt.52-0
(millicandelas
- Opt.52-1) |
10+1
to 10+5
(10+2
to 10+6) |
10+2
to 10+6
(10+3
to 10+7) |
Specifications
|
Measuring
Field Apertures |
Specify
either ½° or 1° aperture (see Lens
Selection and Field Coverage Chart) |
|
Sensitivity
Range |
(see Full-Scale
Sensitivity Chart) |
|
Field Coverage |
see Lens
Selection and Field Coverage Chart |
|
Viewing field |
Bright,
erect 9.2° viewing field with 6X viewing magnification.
(16.6° with optional 3° circular aperture) |
|
Eyepiece |
Large(22mm)
diameter focusing eyepiece with rubber cap. |
|
Standard
Objective Lens |
MS-55(55mm,
f/2.8) MacroSpectar lens. Focuses from 1¾ in.(44mm) to infinity. |
|
Spectral Response(Unfiltered) |
375-1,100 nm |
|
Calibration |
Traceable
to NIST. Standard luminance calibration units are footLamberts but
calibration in "candelas per square meter" is available
upon request. Radiometric calibration is in microwatts per steradian
per square meter. |
|
Response speed |
From 10
microseconds (on least sensitive range) to 200 milliseconds (on most
sensitive range) |
|
Absolute accuracy |
(includes
uncertainty of NIST standards)
±4%
for photometric measurements(of a black body source);
±10%
for radiometric measurements |
|
Relative accuracy |
(repeatability)
±1%
per month;
±2%per year |
|
Operator Controls |
Power,
Sensitivity and Response Speed switches - plus potentiometers for
zeroing the amplifier and zeroing the dark current - are located on
the back control panel. Two knobs on the side control panel are for
filter selection and insertion of a viewing shutter. |
|
Meter Hold |
Push button
on back panel allows transient meter readings to be retained for inspection. |
|
Readout Indicators |
A 3½
digit, no-blinking digital readout has an illuminated Multiplier Indicator |
|
Output signals |
All models
have a 0-2 volt analog output jack, capable of driving any analog
device whose impedance is greater than 10,000 ohms. In addition, all
models can be provided with a BCD output jack (Option 54) |
|
Operating
Temperature |
32°F
to 110°F(0°C to 43°C) |
|
Power Requirements |
117 volts,
±13 volts, 50 to 400Hz, 5 watts maximum; 230 volts, ±40
volts available on request. |
|
Size and weight |
12½ in.
(31.3 cm) x 6¼ in. (15.9 cm) x 5¾ in.(14.6 cm). Weight is
8½ pounds(3.9 kg) |
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