General RSS-1024 Frequently Asked Questions

FAQ Legend:

All Products Product Class (Spectroradiometers) This Product (RSS-1024)

1. General

1. What kind of optical interference filters do the MFR, UVMFR, and SPUV use?

The MFR, UVMFR, and SPUV all use new technology "Ion Assisted Deposition" interference filters. The slit width and effective center wavelength are exceptional and stable. However, while the throughput/transmission of IAD filters is far superiror compared with previous generations of optical filter technologies, we still recommend that yearly factory calibrations.

2. What is the backup power requirement and temperature sensitivity of the RSS or UVRSS?

The DC standby battery keeps the RSS/UVRSS power bus and CPU/detector solid. However, the spectrograph thermal stabilization heaters are on AC, so these are not backed up. If the internal temperature drops due to an AC failure, the unit will shut down in a few minutes to prevent wavelength measurement errors or water from condensing on the optics. Short AC power glitches are OK, but not day long outages. When equipped with the internal data module, the RSS will hold data until you get power back on. The power management methodology was tested extensively on the MFR and it works well. The RSS optics are thermally stabilized with approximately 100 watts of heat, and the instrument is well insulated. Its temperature sensitivity is so small that we cannot measure any at this time.

3. What do I need to know before selecting an radiometer for outdoor use?

You need to know whether you want spectral or broadband data, and whether you want measurements in the thermal Infrared, NIR/visible, UV-A or UV-B.

Next, decide whether you want direct-normal and/or total (global) radiation measurements.

Finally, decide if you need continuous unatended measurements of "campaign mode" measurements. In campaing mode, the instrument is kept out of inclement weather and setup for brief periods of time, such as making ground-truth measurements during a a satellite fly-by. All YES systems work well in both applications because they are weatherproof and thermally stabilized. However, other instruments (e.g. telescopes) are only suitable for campaign mode.

4. The internal operating temperature of the UVB, MFR, UVMFR, SPUV, RSS is about 45° C. Why is this?

To eliminate effects of changing ambient air temperature and solar loading, we thermally stabilize the internal optics of our instruments to above ambient temperature, between 38° C and 45° C, depending on the instrument. The exact temperature is not as important as knowing that the temperature is stable and has been stable since the most recent calibration.