Spectrophotometric Standards AC-930 & AC-1930
This reference material is used for the verification of the transmittance and absorbance scales of visible absorption spectrometers. The AC-930 set consists of three individual absorption glass filters mounted in a metal holder, and one blank holder. The blank holder can be used as a reference when performing verifications. The filters are made of uncoated Schott NG-4 and NG-5 Filter Glass and are polished over the central 5mm X 20mm filter area to a flat-ness of one wave at 633nm and a parallelism of 20 seconds or better. All finished filters are aged with their surfaces exposed for a minimum of six months to allow the newly polished surfaces to stabilize prior to certification. The nominal transmittance values of these filters are 10%, 20%, and 30%, and each filter is certified for transmittance at five wavelengths: 440.0nm. 465.0nm, 546.1nm, 590.0nm, and 635.0nm. The transmittance values of these filters are sufficient to accurately verify absorption spectrometers, with maximum spectral bandwidths ranging from 2.2nm to 6.5nm, for the five wavelengths at which the transmittance values are certified.
NTRM AC-1930:
This reference material is used for the verification of the transmittance and absorbance scales of visible absorption
spectrometers. The AC-1930 set consists of three individual absorption glass filters mounted in a metal holder, and
one blank holder. The blank holder can be used as a reference when performing verifications. The filters are made
of uncoated Schott NG-4 and NG-5 Filter Glass and are polished over the central 5mm X 20mm filter area to a flat-ness
of one wave at 633nm and a parallelism of 20 seconds or better. All finished filters are aged with their surfaces
exposed for a minimum of six months to allow the newly polished surfaces to stabilize prior to certification.
The nominal transmittance values of these filters are 1%, 3%, and 50%, and each filter is certified for transmittance at
five wavelengths: 440.0nm. 465.0nm, 546.1nm, 590.0nm, and 635.0nm. The transmittance values of these filters are
sufficient to accurately verify absorption spectrometers, with maximum spectral bandwidths ranging from 2.2nm to
6.5nm, for the five wavelengths at which the transmittance values are certified.
RECALIBRATION
The certification for each filter set is valid for a period of 1 year from the date of certification. The filters sets should
be returned to Andover Corporation for cleaning and recalibration upon expiration of the certification period. Andover
will supply a new Certificate certifying the Transmittance Values and Transmittance Densities of each filter at five
wavelengths in the visible portion of the electromagnetic spectrum. Andover is a NVLAP accredited laboratory and is
qualified to recalibrate any NTRM 930 and NTRM 1930 filter sets that were originally supplied by Andover
Corporation and other NVLAP accredited laboratories. Contact the Quality Control Department of Andover
Corporation at (888) 893-9992 (Toll Free) for a Recalibration Return Number, and have the number of the set being
returned, available for the Andover Corporation Quality Control person.
Andover Corporation, 4 Commercial Drive, Salem, NH 03079-2800. Tel: 888-893-9992; Fax: 603-893-6508.