PLEASE READ: This notice is hereby amended. Please see below for further details.

The purpose of this amendment is to update the TSI measurements listed in the previous Pre-Solicitation notice.

This Pre-Solicitation notice is hereby revised:

FROM:
Specifically, the TSI measurements shall have an accuracy of 0.01% (100 parts per million based) on Solar Irradiance SI units with a stability of ≤10 ppm (1σ) per year.

TO:
Specifically, the TSI measurements shall have an accuracy range from 0.01% to 0.035% (100 parts per million to 350 parts per million) based on Solar Irradiance (SI) units with a stability of ≤10 ppm (1σ) per year.

Therefore, the response date to this notice has been updated.

Interested organizations may submit their capabilities and qualifications to perform the effort in writing to the identified point of contact not later than 5:00 p.m. eastern time on May 10, 2019.

All remaining information listed in the previous Pre-Solicitation notice remains unchanged.