Step 1: Check the equipment
- Detector capsule: examine the bottom of the tube to ensure the capsules have not assed their expiry date.
- 5 ml syringe (0.2 fl oz) ? the syringe operates freely and the nozzle is not damaged
- Glass jar or closed circuit sample: ensure the sample jar is clean and free from water
Step 2: Fit the capsule
- Remove a capsule from the tube. Handle carefully and do not touch or allow any moisture onto the yellow paper of the capsule
- Close the tube to avoid contamination of other capsules at ambient humidity.
- Check that paper is uniformly yellow, if it is not, discard an use another capsule
- Fit the capsule to the syringe with the plunger in the depressed position
Step 3: Draw a sample
- Use the sample from the visual check you have just completed
- If you do not already have the sample, follow the task breakdown procedures from the Visual Clear and Bright Procedure
Step 4: Immersion
- Immerse the capsule and approximately half of the syringe using a circular motion into the sample
- Ensure you are using gloves that are impervious to fuel
Step 5: Sample
- Pull the plunger to draw 5 ml of fuel sample into the syringe
Step 6: Examine the capsule color
- Withdraw the syringe from the fuel and examine the capsule immediately for any change of color in the centre wetted area of the capsule
Step 7: Results
- If there is no color change, the sample is acceptable
- The color of the centre can change to slight yellow/ green at very low dispersed water concentrations with the change to green becoming progressively more noticeable with increasing water content
- A few green speckles or a slight change in color would be recorder as a "trace," a distinct color change would be recorder as "suspended water."
Step 8: After sampling
- Dispose of the used capsule safely. It can only be used ONCE.
- Empty the contents of the syringe back into the sample container and return into recovery tank
- Complete the documentation
Interpretation of Shell Water Detector Results
The presence of suspended water is indicated by a change in color of the centre portion of the detector capsule. It changes from faint yellow to green if water is detected.
The life for unused Shell Water Detector capsules is nine months from the time of manufacture. The expiry date month and year is marked on the bottom of each tube of capsules. Unused capsules should be stored in their container with the cap screwed tightly to prevent discoloration by humidity. Each capsule must only be used once.