Why Composite Sampling Matters
Grab samples only show one moment in time.
Composite samples show:
👉 what happens over hours or an entire day.
That gives a much more representative result.
Types of Composite Samples
Most common:
- time-based
- flow-proportional
Flow-proportional is usually more accurate.
Step 1: Use Clean Containers
Contamination ruins results quickly.
I always:
- rinse equipment properly
- avoid dirty tubing
- keep lids closed
Step 2: Keep Samples Preserved
Temperature matters.
Samples are usually kept:
- cooled on ice
- refrigerated
This slows biological changes.
Step 3: Mix Properly Before Testing
Solids settle during storage.
Before testing:
👉 mix the sample thoroughly
Otherwise results may be inaccurate.
Common Sampling Mistakes
- poor preservation
- incorrect timing
- contaminated containers
- missed sample intervals
Final Thought
Good lab results start with good sampling.
Poor samples create misleading process data.