STANDARD OPERATION PROCEDURE

Clean the colorimeter

The colorimeter measuring cell may collect sediment or develop a film growth on the inside walls. Cleaning with an acid solution and a cotton swab on a monthly basis is recommended. Depending on sample conditions, it may be necessary to clean the cell more often. If you have “low signal” system alarm the cell may need to be cleaned. If you scroll the “setup” menu and select “ref” you will see a number displayed. A reference number of 2000 or less is an indicator of a dirty cell, a reference number of 20000 or more is typical of a clean sample cell.

Hold procedure

Place the instrument into the HOLD before cleaning the sample cell. Activate the procedure as follows:

a.  Press ENTER then the UP ARROW key to activate for 60 minutes. The Alarm LED will be flashing.

b.  To deactivate the feature, and return to normal operation, press MENU key then the DOWN ARROW key until HOLD OUTPUTS is displayed.

c.  Press ENTER.

d.  Select OFF and press ENTER again.

Colorimeter cell cleaning procedure

1.  Press the MENU key, then press the down ARROW key until the MAINT menu appears. Press ENTER.

2.  Press the down ARROW key to scroll to the CLEAN option. Press ENTER.

3.  Remove the rubber plug on the top of the colorimeter assembly.

4.  Remove the magnetic stir bar using a bent paper clip as a retrieval tool.

5.  Wait until CLEAN flashes on the status line of the display, then fill the colorimeter with 19.2 N Sulfuric Acid Standard Solution (about 3 droppers full).

6.  Allow the sulfuric acid to stand in the colorimeter for 15 minutes.

7.  Insert a wooden cotton swab into opening and clean cell.

8.  Install the clean stir bar.

9.  Replace the rubber plug on top of the sample cell

10.  Press EXIT to return to normal operation.

Additional information can be found in the CL17 Instruction manual located in the file cabinet labeled “Equipment Manuals”.