UNI-T UT366A for Exhaust and Dust Collection Pressure Testing Malaysia

An industrial exhaust or dust-collection system may continue running even when its extraction performance has deteriorated. A blocked filter, closed damper, leaking duct or fan problem can change the pressure throughout the system.

The UNI-T UT366A Digital Manometer can measure gauge pressure and differential pressure at suitable test points, helping factory-maintenance teams investigate changes in filters, fans and exhaust ducts.

Why Pressure Testing Matters

Dust collectors and exhaust systems depend on pressure differences to move contaminated air from the collection point through the duct and filtration equipment.

Pressure measurement can support investigations involving:

Weak extraction at the hood
Dust escaping into the work area
Rapid filter blockage
Fan-performance changes
Closed or incorrectly adjusted dampers
Blocked duct sections
Air leakage
Uneven extraction between branches
Unexpected energy consumption
Changes after maintenance work

Pressure readings should be compared with the equipment specification or an established operating baseline.

Checking Filter Differential Pressure

As dust accumulates on a filter, resistance to airflow normally increases. Measuring pressure before and after the filter helps maintenance teams track this change.

A typical measurement procedure is:

Identify the approved upstream pressure point.
Identify the downstream pressure point.
Connect one pressure hose to each point.
Set the UT366A to differential-pressure mode.
Confirm the required pressure unit.
Operate the system under normal conditions.
Allow the reading to stabilise.
Record the pressure difference.
Compare the result with the manufacturer’s recommended limit.

Do not replace or clean filters based only on a general pressure value. Different filter designs have different operating limits.

What Does High Differential Pressure Mean?

A higher-than-normal pressure drop across the filter may indicate:

Filter loading
Blocked filter media
Moisture inside the filter
Incorrect filter type
Failed cleaning cycle
Compressed-air cleaning problem
Hopper or dust-discharge problem
Excessive airflow
Blocked pressure line
Incorrect P1 and P2 connection

Inspect both the filtration system and the measurement setup before deciding on corrective action.

What Does Low Differential Pressure Mean?

A very low filter-pressure drop does not always mean the filter is clean.

Possible causes include:

Torn filter media
Missing filter element
Air bypass around the filter
Reduced fan speed
Open bypass damper
Duct leakage
Low process airflow
Blocked pressure-test point
Leaking measurement hose
Incorrect pressure connection

A physical filter inspection may be necessary.

Checking Fan Inlet and Outlet Pressure

The UT366A can also compare pressure at the fan inlet and outlet.

This may help identify changes caused by:

Dirty filters
Obstructed ducts
Fan-speed reduction
Incorrect fan rotation
Damaged impeller
Loose belt
Closed damper
Air leakage
System modification

A pressure reading alone cannot confirm the fan condition. Also inspect airflow, motor current, speed, noise and vibration.

Checking Exhaust Hood Suction

Weak suction at an extraction hood may allow dust, fumes or process emissions to escape into the surrounding area.

Pressure checks can help determine whether the problem is located near:

The extraction hood
A branch duct
A damper
The main duct
The filter
The fan
The discharge section

Use approved static-pressure test points. Do not place pressure hoses where they can be drawn into moving machinery.

Air-velocity measurement at the hood may also be required to assess capture performance.

Using the Optional Pitot Tube

With the optional UNI-T Pitot tube, the UT366A can measure air velocity inside a suitable duct.

The compatible Pitot tube is:

350 mm long
8 mm in diameter
Made from 304 stainless steel
Connected using separate black and white silicone hoses

Take measurements at several positions across the duct because air velocity is not normally uniform.

Average velocity can be combined with the internal duct area to estimate air volume.

Dust Can Block the Pressure Line

Fine particles may enter an unprotected pressure hose or test point.

A blocked pressure line can cause:

Slow response
No pressure response
A reading that remains after disconnection
Unstable measurement
Lower-than-expected pressure
Different results between test points

Inspect and clean the system’s pressure-test fittings according to the equipment procedure. Prevent dust from entering the UT366A pressure ports.

Protect the Instrument

The UT366A should measure pressure through a suitable clean and dry connection.

Do not allow:

Dust
Liquid
Condensation
Oil
Hot gas
Corrosive gas
Process chemicals

to enter the pressure ports.

Depending on the application, a suitable filter, trap, isolation arrangement or other protective accessory may be required.

Common Reasons for Unstable Readings

Pressure readings may fluctuate because of:

Pulse-jet filter cleaning
Variable fan speed
Damper movement
Changing process load
Air leakage
Turbulence
Loose hoses
Blocked pressure points
Dust inside the hose
Incorrect test-point location

The MAX, MIN and AVG functions can help document pressure variation, but large fluctuations should still be investigated.

Establish a System Baseline

Record pressure values when the exhaust system is known to be operating normally.

A useful baseline can include:

Equipment identification
Fan speed
Damper position
Filter differential pressure
Fan inlet pressure
Fan outlet pressure
Hood or branch pressure
Duct air velocity
Motor current
Filter condition
Process operating condition

Repeat future measurements at the same locations and under similar load conditions.

UT366A Pressure Range and Functions

The UT366A provides:

Pressure range of ±15.00 kPa
Specified accuracy of ±0.5% full scale at 25°C
Independent P1 and P2 measurement
Differential-pressure mode
Positive and negative pressure LED indicators
MAX, MIN, AVG and HOLD
Backlit display
Unit memory
Magnetic hook

Selectable units include kPa, mbar, psi, mmH₂O, inH₂O and hPa.

Suitable Industrial Applications

The UT366A can support pressure checks in:

Dust-collection systems
Welding-fume extraction
Woodworking exhaust systems
Powder-handling areas
Factory ventilation
Process exhaust
Laboratory extraction
Bag-filter systems
Cartridge-filter systems
General HVAC exhaust systems

It is suitable for factories and maintenance contractors across Selangor, Kuala Lumpur, Johor, Penang and Malaysia.

Enquire About Exhaust Pressure Measurement

For assistance selecting the UNI-T UT366A for filter-pressure drop, fan-pressure or exhaust-duct testing, WhatsApp MTM Precision with the expected pressure range and photos of the available test points.

MTM Precision Sdn Bhd

Showroom & Service Centre:
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia

Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my