DRAFT SOW (ACQ 43963) SRM2241a glass .pdf

Statement of Requirements

SRM 2241a Glass Units

I. BACKGROUND

The Organic Chemical Metrology Group (OCMG) at the National Institute of Standards and Technology (NIST) needs to acquire 200 units of a glass artifact for the purposes of producing a new lot of Standard Reference Material (SRM) 2241 (Relative Intensity Correction Standard for Raman Spectroscopy: 785 nm Excitation). The new lot will be released as SRM 2241a. These units must be made to the exact specifications described below such that the absorbance and emission characteristics of the glass units match previous NIST SRM 2241 units as closely as possible.

II. SPECIFICATIONS

The Contractor shall deliver two hundred (200) glass substrates that meet the following minimum specifications:

Glass making specifications

• The glass must have the following composition:

Oxide weight % SiO2 67.35 Na2O 6.95 B2O3 25.65

Cr2 O3 0.05

• The glass must be made at a high temperature of approximately but no lower than 1415 °C.

• The glass must be annealed to eliminate stress and strain as observed using polarized light

Cutting, polishing and finishing

• Each glass unit must have Dimensions 10.0 mm +/- 0.1 mm by 10.0 mm +/- 0.1 mm by 1.65 mm +/-

0.05 mm.

• Each glass unit must have one of the 10 mm x 10 mm faces polished and the opposite face frosted.

• The polished face must be finished with a scratch-dig tolerance of 20-10.

• The polished face must be flat to 4 fringes at 633 nm.

• The frosted surface must be frosted to give 1 micron to 3-micron rms surface roughness (400 grit alumina sanding).

Glass optical specifications

• Measurement Conditions All emission specifications listed below must be evaluated using a Raman spectrometer system equipped with a continuous-wave 785 nm excitation laser. The system must be capable of measuring Raman/luminescence spectra down to at least 200 cm-1 from the excitation line with minimal background contribution (<5% of the absolute emission intensity of the glass units across the 200 cm-1 to 3500 cm-1 Raman shift range). Conventional fluorescence spectrometers are not suitable for these measurements.

• Absolute Emission Intensity The absolute emission intensity values must match that of the original SRM 2241 units within 10% from 200 cm-1 to 3500 cm-1 Raman shift relative to 785 nm (797.5 nm to 1082.4 nm).

• Emission Spectrum The normalized emission spectrum of the glass units must match that of the original SRM 2241 units within 5% from 200 cm-1 to 3500 cm-1 Raman shift relative to 785 nm (797.5 nm to 1082.4 nm).

• Spatial Homogeneity Each unit must be spatially homogeneous with respect to the following emission characteristics when excited by a 785 nm laser focused to a spot size ≤10 µm on the polished surface.

o Absolute emission intensities must be uniform within 5% across each unit.

o A two-dimensional spectral mapping of the polished surface, with data acquired at step sizes of <50 µm in each dimension, must yield a normalized emission dataset exhibiting a ≤2% RSD across the 200 cm-1 to 3500 cm-1 Raman shift range.

• Between-Unit Homogeneity Across the lot of 200 glass units, the dataset of normalized emission spectra must exhibit a ≤2% RSD over the 200 cm⁻¹ to 3500 cm⁻¹ Raman shift range. A single representative spectrum per unit (e.g., the average spectrum from the spatial homogeneity mapping) should be used for this determination.

• Optical Quality Each unit must be of high optical quality such that it is free of bubbles and stria.

Prior to shipment of the glass units to NIST, the Contractor must provide a report of analysis that verifying that the full lot of material meets the above physical and optical specifications. The Contractor must provide the spectral data collected to determine this in a readily readable format.

after vial filling and prior to shipment of the vials to NIST. The Contractor shall provide NIST with a Certificate of Analysis indicating 25(OH)D2 and 25(OH)D3 concentrations of each Level of SRM 972b. This data must be provided to NIST as a PDF via email to the SME before shipment of the entire production lot.

III. DELIVERABLES

Description Quantity Due Date

SRM 2241a Glass Units

Two-Hundred (200)

Within 90 calendar days of award delivered to the Subject Matter Expert (SME)

IV. ACCEPTANCE CRITERIA

Acceptance will occur once Government specifications are verified within 30 days of delivery. Acceptance will be based on verifying that all specifications have been met on a randomly selected batch of 15 units from the 200 delivered.