10 Common Suspended Solids Testing Mistakes Malaysia
10 Common Suspended Solids Testing Mistakes Malaysia
Suspended-solids readings can be affected by sampling location, particle settling, air bubbles, dirty measuring bottles and incorrect instrument selection.
An unexpected result does not always mean that the meter is faulty.
Avoiding the following common mistakes can improve the consistency of measurements taken with portable instruments such as the Qiwei SS-500B Suspended Solids Meter.
Mistake 1: Collecting an Unrepresentative Sample
Water conditions may differ between the surface, middle and bottom of a tank.
A sample collected near settled sludge may contain unusually high solids, while a surface sample may contain fewer heavy particles.
Better Practice
Use a fixed sampling point.
Keep the sampling depth consistent.
Avoid surface foam.
Avoid settled material unless it is the investigation target.
Record the sampling location.
Mistake 2: Allowing Particles to Settle
Suspended particles may begin settling immediately after collection.
If the operator waits too long, the measured sample may contain fewer particles than the original water.
Better Practice
Mix the sample gently.
Transfer it promptly.
Measure using consistent timing.
Record the delay between mixing and measurement when necessary.
Mistake 3: Shaking the Sample Too Aggressively
Strong shaking can introduce air bubbles and foam.
These may interfere with an optical measurement and create unstable results.
Better Practice
Mix the sample gently. Allow large bubbles to clear without waiting so long that the suspended particles settle.
Mistake 4: Touching the Measuring Bottle
Fingerprints, oil and moisture on the bottle may affect the optical path.
Better Practice
Hold the bottle near the cap or upper section.
Wipe the outside with a clean, lint-free material.
Confirm that the measurement area is dry.
Avoid touching it again before inserting it into the meter.
Mistake 5: Using a Dirty or Scratched Bottle
Residue, chemical film, permanent stains and scratches can cause inconsistent readings.
Better Practice
Clean the bottle immediately after use. Compare both bottles using the same sample and replace any bottle that is scratched or permanently cloudy.
Mistake 6: Confusing Suspended Solids with Turbidity
Suspended solids and turbidity do not provide the same result.
Suspended solids are normally reported in mg/L.
Turbidity is normally reported in NTU or FNU.
There is no universal conversion between the two.
Better Practice
Confirm the required parameter and unit before selecting an instrument.
Mistake 7: Confusing Suspended Solids with TDS
TDS represents dissolved substances and is commonly estimated through conductivity.
A basic TDS meter does not directly measure suspended particles.
Better Practice
Ask whether the customer needs:
Suspended solids in mg/L
TDS in ppm
Conductivity in µS/cm
Turbidity in NTU
Do not select the instrument based only on the word “solids.”
Mistake 8: Ignoring the Measurement Range
The Qiwei SS-500B has a published range of 0–500 mg/L.
A highly concentrated wastewater or sludge sample may exceed this range.
Better Practice
Review historical laboratory results and determine the normal and maximum concentration before ordering.
If the sample is over range, do not report 500 mg/L as the actual result.
Mistake 9: Treating Resolution as Accuracy
The SS-500B displays results in 1 mg/L increments.
This does not automatically mean that every reading is accurate within ±1 mg/L.
Better Practice
Review the complete manufacturer specification for:
Accuracy
Repeatability
Linearity
Calibration method
Measurement principle
Sample limitations
Customers preparing tenders should not rely only on the number of displayed digits.
Mistake 10: Using Portable Results as Automatic Compliance Results
A portable meter is useful for:
Operational screening
Process comparison
Field troubleshooting
Trend monitoring
Selecting samples for laboratory analysis
However, official reporting may require a recognised laboratory method and accredited result.
Better Practice
Confirm the required procedure with the relevant authority, environmental consultant, customer or laboratory.
Additional Mistake: Failing to Record the Conditions
A reading without supporting information may be difficult to interpret.
Record:
Date and time
Sampling point
Suspended-solids result
Sample appearance
Production activity
Flow condition
Chemical dosing
Weather or rainfall
Operator
Corrective action
A monitoring trend is more useful than an isolated number.
Recommended Measurement Procedure
For routine portable testing:
Select a representative sampling point.
Collect the sample in a clean container.
Mix the sample gently.
Avoid introducing bubbles.
Fill a clean measuring bottle.
Wipe the outside surface.
Measure before particles settle.
Repeat an unexpected result.
Record the measurement.
Clean the bottle immediately after use.
Use the same procedure for every sampling point and operator.
How to Check an Unexpected Reading
If a result seems incorrect:
Collect a fresh sample.
Clean both sample bottles.
Fill them from the same well-mixed sample.
Measure both using identical timing.
Repeat each measurement.
Compare with a stable reference or laboratory result.
Check calibration and battery condition.
Arrange an inspection if verification fails.
This helps distinguish sample variation from instrument problems.
About the Qiwei SS-500B
The SS-500B provides:
Measurement range: 0–500 mg/L
Displayed resolution: 1 mg/L
AC adaptor or AA-battery operation
Two measuring bottles
Portable field and indoor use
It is suitable for routine suspended-solids screening when the application and concentration match its specifications.
Contact MTM Precision
For the Qiwei SS-500B Portable Suspended Solids Meter, water-quality instrument selection, troubleshooting assistance or quotation, contact:
MTM Precision Sdn. Bhd.
Professional Test & Measurement Solutions Partner in Malaysia
Website: www.mtmpre.com.my
Email: mtmpre@yahoo.com
WhatsApp: +6016-660 7346
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia.
Malaysia Coverage:
Selangor, Kuala Lumpur, Johor, Penang, Melaka, Negeri Sembilan, Perak, Pahang, Kedah, Perlis, Terengganu, Sabah and Sarawak.
15 Sep 2026
