Calibrating the X-Rite 811
The X-Rite 811 is a fully digital instrument. Even so, it requires periodic calibration to compensate for the aging of its electronic components, especially the lamp. As the 811 is both a reflection and a dual-mode transmission instrument there are three individual calibrations that must be performed. The 811 also has an interesting quirk; the TRANSMISSION sections of the electronics MUST be calibrated before the reflection section. With a new 811 you will have received two calibration materials - a reflection plaque (PN 302-12) and a transmission film (PN 810-68). These are laboratory certified materials. They should be cared for and replaced every 18 months. An expiration date is printed on both the media and on their protective envelopes. To calibrate apply power to the densitometer; wait until its self test is concluded:
Calibrating the Transmission optics
- Press the "T/R" key until the letter "TA" appears in the LCD panel.
- Next, press the "CAL" key. The densitometer will respond with "calibrate NO YES".
- Press the key beneath the word "YES". The densitometer will immediately display the number currently stored in its visual Hi calibration channel.
- Remove the calibrated test film from its protective cover. Notice that one of the steps is marked with the word "CAL". Beneath is written the laboratory certified values for that step. There are three numbers - one each for "R" (red), "G" (green), and "B" (blue). The value currently displayed by the 811 should match! If the number does not match you may edit the value (up or down) by pressing the keys beneath the small arrows.
- After ensuring a match for the visual channel, press the "COLOR" key. The densitometer will next show the value for the "R" (red) channel. Again this number should match the value written on the test film.
- As with the visual channel, press the "COLOR" key after you have verified a match between the displayed value and the film. Continue in this manner until all four channels have been verified.
- After the forth channel (blue) has been edited, press the "COLOR" one more time. The unit will now display "READ TRN NO FILM".
- The densitometer is prompting you to read. At this time however, DO NOT PLACE THE FILM BENEATH THE HEAD. The densitometer just needs to read the deck alone! Simply press the head down firmly and wait until numbers appear in the LCD display. When you see the flashing numbers appear, just release the reading button.
- The densitometer will now prompt "READ TRN STD:Hi". With this prompt the densitometer does want to 'see' your film. Place the transmission test film beneath the reading head so that the "CAL" step completely covers the illuminated aperture. Again press the reading button firmly and wait until numbers appear.
- That's it! The transmission Status A portion of the densitometer is now calibrated.
- Return to the top of these instructions. This time press the the "T/R" key until the letter "TM" appears in the LCD panel. Continue exactly as you did for the "A" section.
- Done with transmission. You should next return the certified test film to its protective cover.
Calibrating the Reflection optics
- Press the "T/R" key until the letter "R" appears in the LCD panel.
- Next, press the "CAL" key. The densitometer will respond with "calibrate NO YES".
- Press the key beneath the word "YES". The densitometer will immediately display the number currently stored in its visual Lo calibration channel (V:Lo).
- Remove the calibrated test plaque from its protective envelope. Notice that there are three targets, a white, a gray, and a black. In this calibration only the white and the black are measured. The gray target is only used by X-Rite's repair technicians.
- On the envelope you will find values written in for each of these targets. There are four numbers for each step - one each for "V" (visual), "R" (red), "G" (green), and "B" (blue). The value currently displayed by the 811 should match the visual Lo! If the number does not match you may edit the value (up or down) by pressing the keys beneath the small arrows.
- After ensuring a match for the visual channel, press the "COLOR" key. The densitometer will next show the value for the "R" channel (R:Lo). Again this number should match the value written on the test plaque.
- As with the visual channel, press the "COLOR" key after you have verified a match between the displayed value and the plaque. Continue in this manner until all four channels' Lo values have been verified.
- The densitometer continues by displaying the number currently stored in its visual Hi calibration channel (V:Hi).
- The value currently displayed by the 811 should match the visual Hi! If the number does not match you may edit the value (up or down) by pressing the keys beneath the small arrows.
- After ensuring a match for the visual channel, press the "COLOR" key. The densitometer will next show the value for the "R" channel (R:Hi). Again this number should match the value written on the test plaque.
- As with the visual channel, press the "COLOR" key after you have verified a match between the displayed value and the plaque. Continue in this manner until all four channels' Hi values have been verified.
- After the forth channel (blue) has been edited, press the "COLOR" one more time. The unit will now display "READ REFL STD:Lo".
- The densitometer is prompting you to read. Place the reflection standard onto the deck locating the White target beneath the reading head. Simply press the head down firmly and wait until numbers appear in the LCD display. When you see the flashing numbers appear, release the reading button.
- The densitometer will now prompt "READ REFL STD:Hi". Move the reflection plaque until the Black target is beneath the reading head. Again press the reading button firmly and wait until numbers appear.
- That's it! The reflection portion of the densitometer is now calibrated. You should next return the certified test plaque to its protective cover.
