Hach SP-51 Manual Básico Del Usuario página 20

9.8 Replace the tubing
The manufacturer recommends that one tube is replaced at a time. Refer to the documentation
supplied with the maintenance kit.
9.9 Clean the colorimeter
Chemical exposure hazard. Obey laboratory safety procedures and wear all of the
personal protective equipment appropriate to the chemicals that are handled. Refer to
the current safety data sheets (MSDS/SDS) for safety protocols.
The colorimeter measuring cell can collect sediment or cause layers to grow on the inside walls.
Clean the cell with an acid solution and a cotton swab on a monthly basis.
Items to collect:
• Sulfuric acid standard solution, 19.2 N, 100 mL MDB
• Wooden or paper cotton-tipped swab
• Bent steel paper clip
• Stir bar (optional)
1. Remove the plug from the top port of the colorimeter. Refer to
2. Remove the magnetic stir bar with a bent steel paper clip as a retrieval tool.
3. Use the pipette to add 2–3 drops of 19.2 N sulfuric acid standard solution in the colorimeter.
Note: Lower normality sulfuric acid is not sufficient to clean the colorimeter.
4. Let the sulfuric acid stay in the colorimeter for 15 minutes.
5. Use a wooden or cotton-tipped swab to clean the interior surfaces of the colorimeter cell. Move
the cotton-tipped swap gently up and down.
Note: Do not use a plastic swab to clean the colorimeter with sulfuric acid. The acid will dissolve the plastic.
6. Make sure that the measurement cell is dry.
7. Clean the stir bar with water or alcohol or replace the stir bar.
8. Replace the plug in the top port of the colorimeter.
9.10 Replace the sample conditioning filter
Examine the sample conditioning filter regularly when lots of solids are in the sample. Replace the
sample conditioning filter if necessary. Refer to
maintenance interval. Refer to the documentation supplied with the installation kit.
9.11 Replace the fuse
Electrocution hazard. Remove power from the instrument before doing maintenance or
service activities.
Fire hazard. Use the same type and current rating to replace fuses.
Remove the two fuses (F1 and F2) and replace them with two new fuses with the same
specifications, T, 1.25 A, 250 V. The same fuse rating is used for the 115 V and for the 230 V
operation. Refer to Figure 10
20 English
W A R N I N G
Maintenance schedule
D A N G E R
D A N G E R
on page 14.
Figure 13 on page 16.
on page 18 for the