Ocean Optics RPH-1 - Manual

RPH-1 Reflection Probe Holder
The RPH-1 R EFLECTION P ROBE H OLDER is an anodized aluminum platform with machined holes at 45° and 90° to
hold our R200 Reflection Probes or other 0.25" O.D. probes during reflection measurements. Common applications
include measuring the reflection properties of mirrors and anti-reflection coatings, and measuring the visual
properties of color in paints, graphic arts, plastic, and food products.
Operation
Reflection is the return of radiation by a surface, without a change in wavelength. The reflection may be:
! Specular, in which the angle of incidence is equal to the angel of reflection. If taking specular reflection
measurements, position the reflection probe in the 90° aperture of the RPH-1.
! Diffuse, in which the angle of incidence is not equal to the angle of reflection. If taking diffuse reflection
measurements, position the reflection probe in the 45° aperture of the RPH-1.
Every surface returns both specular and diffuse reflections. Some surfaces may return mostly specular reflection,
others more diffuse reflection. The glossier the surface, the more specular the reflection.
Specular Reflectance Measurements
For a specular reflection measurement, attach the illumination leg of your reflection probe to a light source, and the
read leg to the spectrometer. Place the end of the probe in the 90° aperture of the RPH-1. Use the cap screw on the
holder to secure the probe at the desired distance from the sample.
1.
First, take a reference spectrum. Make sure nothing is blocking the light path going to your reference. Place the
reflection probe/probe holder over a first-surface mirror. Take the reference reading.
2. Next, take a dark spectrum. Completely block the light path going to your sample. Do not turn off the light
source. Take the dark reading.
3. Finally, take your reflection measurement. Make sure the sample is in place and nothing is blocking the light
going to your sample. If using OOIBase32, click on the Transmission icon to take your spectrum. (The
Transmission Mode uses the same formula for transmission and reflection measurements.)
Diffuse Reflectance Measurements
For a diffuse reflection measurement, attach the illumination leg of your reflection probe to a light source, and the
read leg to the spectrometer. Place the end of the probe in the 45° aperture of the RPH-1. Use the cap screws on the
holder to secure the probe at the desired distance from the sample.
1.
First, take a reference spectrum. Make sure nothing is blocking the light path going to your reference. Place the
reflection probe/probe holder over a diffuse standard. Take the reference reading.
2. Next, take a dark spectrum. Completely block the light path going to your sample. Do not turn off the light
source. Take the dark reading.
3. Finally, take your reflection measurement. Make sure the sample is in place and nothing is blocking the light
going to your sample. If using OOIBase32, click on the Transmission icon to take your spectrum. (The
Transmission Mode uses the same formula for transmission and reflection measurements.)
Operating Instructions: RPH-1