To Next Page

To Previous Page

AQ-00073-000, Rev. 7 12

reflectance standard or sample against the respective port. Three sample holders are provided

with the accessory for mounting a sample either at 0° or 8° angles of incidence. The sample

holders mount directly to the port frame at each end of the sphere.

The sphere detector is a silicon photodiode installed at the detector port at the bottom of the inte-

grating sphere. The photodiode operates in photovoltaic mode; the detector output is conditioned

by the preamplifier board for compatibility with the instrument electronics. Detailed information

on the photodiode is provided in Appendix A.

Transfer Optics

The transfer optics of the RSA-PE-20 accessory direct the spectrometer sample beam to the

transmittance port on the integrating sphere. The sample beam is the front beam in the accessory.

As shown in Figure 6, mirrors labeled M1, M2 and M3 guide the sample beam through the sam-

ple transmittance port and onto the sample reflectance port at normal incidence. All mirrors are

AlMgF

coated. Mirrors M1 and M2 are flat. Mirror M3 is a spherical mirror that condenses the

sample beam onto the target sample. The reference beam passes through the accessory unim-

peded.

Loading the Sample Holders

Both transmittance and sample reflectance ports are 5/8-inch holes at either end of the accessory

sphere. The transmittance port is closest to mirror M3. A sample holder clamp fits over a dove-

tail extension located underneath each port, securing the reflectance standard or sample tightly

against the port opening.

The sample holder with the 8

wedge should be installed at the sample reflectance port when

taking 8

hemispherical measurements. The 0

sample holder should be installed at the sample

reflectance port when taking diffuse measurements with the specular component excluded. Fig-

ure 8 describes the proper way to load the sample holder. When mounting a sample or reflec-

tance standard at any port, you should make sure the reflecting surface lies flat against the wedge

and completely fills the port surface area.

To remove the sample holder at the sample reflectance port, loosen the set screws along the side

of the respective wedge and remove the entire sample holder assembly.

Labsphere RSA-PE-20 User Manual

Questions and Answers: