PHOTOVOLT TECHNICAL NOTE
Procedure For Set-Up And Calibration Of Photovolt 577 Reflectance Meter

1. Plug the 577 meter into the appropriate electrical outlet (110 or 220V). Line fluctuation should not be more than 10% of the normal rate. For the W search unit use HI gain and for the Y and T search units use LO gain. Ensure that the proper fuses have been installed by referring to the 577 Manual.

2. Plug in the appropriate search unit to the fitting on the back of the 577.

3. Before use, the 577 must be zeroed and calibrated. Zeroing is done with the black cavity standard placed over the search unit and calibrated by replacing the black cavity standard with the brightness plaque for use with the W search unit or a tristimulus plaque with the Y or T search unit.

4. To zero the 577, place the black cavity standard on the search unit. Press CHANGE and STD. The display will read 0.0 or.0.

5. To calibrate the 577, remove the black cavity standard and place the tristimulus plaque in place on the Y or T search unit.

5.1 To calibrate the T search with an amber filter, rotate the amber filter into position. Press A, CHANGE, and STD. In this position the displayed numbers can be changed. Press A to change the first number, B for second number and G for third number. Press STD to retain this value in the memory. Manually insert filters into the Y search unit and proceed as above.

5.2 Repeat with the B channel and the G channel to key in the blue and green tristimulus values in succession. Press STD after each number.

6. The W search unit has a built-in blue filter (different from the blue filter of the Y and T search unit) and is zeroed as in 3 and 4 above. Use only the B channel here and ignore the A and G channels when using the W search unit.

7. The 577 is now ready for use with your samples.

8. Brightness is read from the display after zeroing and calibrating as above using the W search unit. CIE color coordinates are obtained from the three tristimulus readings using the T search unit with your samples and the 577 COMPUTER PROGRAM. The program is offered free to 577 owners. Contact Photovolt Technical Service at 800-222-5711, ext. 143, for a copy.

9. Daily zeroing and calibration are a must.

1999-08-25