Qiwei PH-220W for Industrial Wastewater pH Testing Malaysia
Industrial wastewater pH can change because of chemicals, cleaning processes, production materials and treatment-system conditions. Regular pH checking helps factory operators identify abnormal water conditions before the wastewater moves to the next treatment stage or discharge point.
The Qiwei PH-220W External Electrode Portable pH Meter is suitable for routine pH and temperature checks in industrial wastewater, treatment tanks and collected water samples.
Its external wired electrode can be placed inside a sample container or accessible tank while the main display remains in the operator’s hand.
The Qiwei PH-220W is available from stock at MTM Precision Malaysia.
Why Is Wastewater pH Important?
pH indicates whether wastewater is acidic, neutral or alkaline.
Incorrect pH may affect:
Wastewater-treatment efficiency
Chemical dosing
Biological treatment
Coagulation and flocculation
Corrosion of pipes and tanks
Equipment service life
Downstream water quality
Regulatory compliance
A sudden pH change may also indicate an abnormal production process, chemical spill, dosing-system problem or change in incoming wastewater.
Where Can the Qiwei PH-220W Be Used?
The Qiwei PH-220W is suitable for routine checks at locations such as:
Incoming wastewater
Equalisation tanks
Neutralisation tanks
Chemical-treatment tanks
Biological-treatment tanks
Clarifier samples
Process-water tanks
Final treated-water samples
Drainage inspection points
Laboratory sample containers
Operators should only place the electrode into safe and accessible measuring points. Sampling from hazardous, hot or restricted areas must follow the facility’s approved safety procedure.
Why Is an External Electrode Useful?
An ordinary pH pen requires the complete sensor end of the instrument to be placed into the liquid.
The Qiwei PH-220W uses an external wired electrode, allowing the operator to immerse only the probe.
This design is useful when:
Testing inside a sample bottle
Measuring water in a narrow container
Reaching an accessible section of a treatment tank
Keeping the display away from splashing water
Comparing several collected samples
The measuring point is difficult to reach with a normal pH pen
The main instrument should still be protected from water, chemicals and accidental immersion.
Key Features
0.01 pH resolution
Measures pH and temperature
External wired pH electrode
Three-point pH calibration
Portable and lightweight
Suitable for factory and field checks
Convenient for tanks and sample containers
Clear digital display
Available from stock in Malaysia
Main Technical Specifications
Model: Qiwei PH-220W
pH Measuring Range: 0.01 to 14.00 pH
pH Resolution: 0.01 pH
Temperature Range: 0 to 50°C
Temperature Resolution: 0.1°C
Calibration: Three-point pH calibration
Electrode Type: External wired pH electrode
Power Supply: Four 1.5V batteries
Dimensions: Approximately Ø40 × 185 mm
Weight: Approximately 88g
Specifications and supplied accessories may vary according to the latest production batch. Please confirm the current configuration with MTM Precision before ordering.
How to Measure Wastewater pH
Wear the required personal protective equipment.
Collect the sample using the facility’s approved sampling procedure.
Use a clean and chemically compatible sample container.
Confirm that the sample temperature is within the instrument’s specified range.
Calibrate the pH meter using fresh buffer solutions.
Rinse the electrode before measurement.
Place the electrode into the sample.
Stir or move the probe gently to remove trapped air bubbles.
Wait for the reading to stabilise.
Record the pH value, temperature, location and sampling time.
Rinse and clean the electrode after measurement.
Avoid returning a tested sample to the original tank or container because this may cause contamination.
Why Should Sampling Location Be Recorded?
Wastewater pH can vary at different stages of the treatment process.
For example:
Incoming wastewater shows the condition before treatment.
Equalisation-tank readings show whether different wastewater streams are being balanced.
Neutralisation-tank readings help operators evaluate chemical dosing.
Final-water readings indicate the condition after treatment.
Recording the sampling location makes the result more useful for troubleshooting and process control.
What Can Cause a Sudden pH Change?
Possible causes include:
Acid or alkaline chemical spill
Incorrect chemical dosing
Empty dosing tank
Dosing-pump failure
Production-process changes
Cleaning chemical discharge
Unexpected wastewater entering the system
Poor mixing inside the treatment tank
Sensor contamination
Incorrect calibration
An unexpected result should be verified using a freshly calibrated meter before major treatment adjustments are made.
Why Does the pH Reading Keep Moving?
An unstable wastewater pH reading may be caused by:
Dirty or coated electrode
Oil, grease or chemical residue
Suspended solids around the sensor
Dry electrode
Old calibration buffer
Sample temperature changes
Insufficient stabilisation time
Damaged or ageing electrode
Wastewater can contaminate a pH electrode more quickly than clean water. Proper cleaning after each measurement is important.
Electrode Cleaning After Wastewater Testing
After measuring wastewater:
Rinse the electrode immediately
Remove visible residue carefully
Use a suitable electrode-cleaning solution when required
Do not aggressively wipe the glass sensing surface
Recondition the electrode if the response becomes slow
Store it using the correct pH-electrode storage solution
Recalibrate before important measurements
Different contaminants may require different cleaning procedures. Oils, proteins, mineral deposits and chemical residues should not automatically be treated using the same cleaning agent.
Can the PH-220W Be Used for Regulatory Reporting?
The Qiwei PH-220W is suitable for routine operational monitoring, troubleshooting and preliminary field checks.
Official regulatory reporting may require:
Approved sampling procedures
Specific test methods
Traceable calibration
Documented quality-control checks
Laboratory testing
Proper sample preservation
Qualified personnel
Customers should follow the latest requirements of the relevant Malaysian authority and their approved environmental-management procedure.
A portable pH meter should not automatically be treated as a replacement for an accredited laboratory test.
What Other Wastewater Parameters Should Be Tested?
pH alone cannot provide a complete assessment of wastewater quality.
Depending on the application, other parameters may include:
Chemical Oxygen Demand
Biochemical Oxygen Demand
Total Suspended Solids
Turbidity
Conductivity
Total Dissolved Solids
Dissolved oxygen
ORP
Ammonia nitrogen
Temperature
Residual chlorine
MTM Precision supplies a range of water-quality instruments for portable and laboratory applications.
Who Should Use the Qiwei PH-220W?
The Qiwei PH-220W is suitable for:
Factory maintenance departments
Wastewater-treatment operators
Environmental service contractors
Water-treatment companies
Electroplating factories
Food and beverage plants
Chemical-processing facilities
Palm-oil and agricultural operations
Building maintenance teams
Educational and training laboratories
Qiwei PH-220W Available in Malaysia
The Qiwei PH-220W External Electrode Portable pH Meter is available from stock at MTM Precision Malaysia.
Customers may contact us for the current quotation, stock availability, supplied accessories and electrode information.
Contact MTM Precision
MTM Precision Sdn. Bhd. (744811-A)
Telephone: +603-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com / enquiry@mtmpre.com.my
Website: www.mtmpre.com.my
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor,
Malaysia.
18 Sep 2026
