Call 1-800-CALUMET for availability
Check Store Availability
Amber. Used to convert the resonse characteristic of an S-4 type photocell (as in a densitometer) to the luminosity response of the eye. Note: Due to the relatively high sensitivity of an S-4 type photocell in the red and near infrared, density readings above 2.0 should be interpreted with caution when measuring dye samples.