Hach DR 3900 Manuel D'utilisation De Base page 114

Self-check
Each time the instrument is powered up, a test program begins.
This procedure, which takes approximately two minutes, checks the
system, lamp, filter adjustment, wavelength calibration and voltage.
Each test that functions correctly is marked accordingly.
The Main Menu is displayed when diagnostics are completed.
Note: In the event of further error messages during the test program,
refer to Troubleshooting, Seite 120.
Sleep mode
The instrument can be put into sleep mode.
1. Briefly press the power button next to the display.
The "Sleep mode" message is shown. The display will then switch
off automatically.
2. To switch on, press the power button next to the display.
The self-check will start automatically.
After that, the instrument is ready to use.
Power off the instrument
1. Press the power button next to the display for approximately
5 seconds.
Standard programs
Tips for the use of the touch screen
The whole screen responds to touch. To choose an option, tap with a
fingernail, fingertip, an eraser or a specialised stylus. Do not press the
screen with a sharp object, such as the tip of a ballpoint pen.
• Do not place anything on top of the screen, to prevent damage or
scratches on the screen.
English 113