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Cleanrooms Pressure Qualification

Cleanrooms Pressure Qualification

Qualification tests are carried out to guarantee optimum product quality from all manufacturing and pharmaceutical research companies. These tests verify whether ambient cleanroom conditions affect product quality. If environmental cleanroom parameters affect the product, reviews are conducted with regards how conditions can be reduced, so that high output standards are adhered to.

What Is Differential Pressure?

When a cleanroom door is opened, impurities can find their way in, causing a reduction in pressure. Conversely, when the pressure within a cleanroom is too high, energy is wasted.

Temperature, humidity, airflow and pressure are all cleanroom parameters that have to be well managed.  Pressure is most critical and a key parameter; for instance, when pressure is combined effectively with the other two parameters, cleanrooms function properly.

Computed pressure deviation between two points gives the differential pressure; for example, if the pressure at point A is 200psi and point B is 100psi, the differential pressure is 100psi (200psi-100psi). Differential pressure is critical, as tiny pressure differences can have a huge effect on cleanrooms, as well as manufacturing and HVAC (Heating, Ventilation and Air-conditioning) laboratories. Differential pressure ensures less clean areas within a cleanroom don’t spread contamination to cleaner areas.

Cleanroom operational safety is monitored and improved by measuring air flow velocity/pressure. To achieve pressurisation control will depend on differential pressure control and airflow tracking. Pressurisation control of a cleanroom is mandatory to confirm and maintain cleanroom parameters. Cleanrooms require surrounding areas be positively pressurised to create buffer zones and reduce accidental contamination.

Pressure And The Cleanroom

A cleanroom system is akin to having a mini-building within a larger building. A cleanroom has its own HVAC system, flooring, lighting and differential pressure. The exterior wall of a building should never be used as a cleanroom wall. Also, entry or exit doors should never be the same points for a cleanroom’s interior, because of wind pressure. The implication of a 30 mile per hour wind is a wind pressure of .47 ‘‘w.g. (116.2 Pa). Subsequently, an open door will cause IAQ (Inside Air Quality) problems.

Room pressurisation is a necessity to ensure product integrity. Opening an average sized single width door increases leakage area by 20 square feet or more on average. The implication is a disruption with an appreciable, differential static pressure value. To create a balance, there will need to be an excessive amount of differential airflow.

Measurement Of Differential Pressure

A visual indicator gauge is deployed to compute differential pressure. It is designed to compute and read a differential between two pressure points within a process environment. The gauge is connected to pressure monitored points from two inlet ports. If the gauge isn’t deployed, a control system or operator would need to manually monitor two separate gauges before disclosing their differential readings. This would be a cumbersome process.

We are cleanroom experts and market leaders who offer the DE21 transmitter, which observes and verifies the slightest differential pressure in cleanrooms.

The DE21 is a 2-wire DIN capturing, computing and reading device. It comes with capacity measuring cells to cover diverse low-pressure range areas, combined with a high overpressure guard feature. DE21 instruments provide lengthy, drift-free operations and high precision stability, since no signal broadcast is needed. DE21s are mainly deployed in laboratories, industrial furnaces, filters, blowers and packaging machines.

Key DE21 Features

  • Selectable units Pa, mbar, inWC and kPa through a DIP Switch
  • Comes with a high guard pressure protection
  • Accurate measurement with lowest gauge feature, which can determine differential pressure of non-corrosive and restrictive gaseous exchange
  • Long-term stable capacitor sensor element and a high precision feature
  • Four-character LCD screen on the front, displaying differential pressure within pressure areas


DE21 supports the following:

  • Flow measurement
  • Filter monitoring
  • Low pressure measurement to support comfort control and automation


DE21 Functionality

The DE21 instrument provides excellent sensor stability and repeatability. This is possible with the presence of an ultra-thin single crystal diaphragm (patented silicon-on-glass technology feature).

Mechanical degradation won’t occur in the long run, because the silicon diaphragm sensor isn’t manufactured with organics or glue. Notably, it’s been proven that organics contribute to a drift or unwanted degradation.

DE21 applications

  • Helps in monitoring cleanrooms and laboratories
  • Supports filters, fans and packing machines
  • Supports the pharmaceutical industry


Testo 521-3 Device For Differential Pressure

The Testo 521-3 is a computing device for differential pressure in cleanrooms. With high level precision and clear data information, its integrated temperature-compensated sensor reads measurements to an accuracy of up to ± 0.5 Pa. There is a wide range of units to choose against pressure measurement, which include: mbar, bar, hPa, Pa, kPa, mmH2O, inH2O, psi and torr.


  • The Testo 521-3 has a high computable capability range
  • It records the smallest pressure differences, effortlessly
  • It can fulfill differential pressure readings for flue inspections or cleanroom use, due to its resolution capabilities
  • It features an integrated differential pressure sensor, which has a 0.5% Pa accuracy
  • It has calculation attributes for velocity and volume flow, via a pilot tube
  • It has automatic recognition functions for all connected probes
  • It has a RS232 interface
  • It features two probe inputs for additional temperature and pressure
  • It has a battery recharging instrument and a mains connection
  • It features two probe inputs for additional temperature and pressure
  • It features timed mean calculation and also has a multi-point
  • Rate is two times in a second, but four times for fast readings
  • It has a point matrix, seven segment display and LCD display
  • Has a memory of 100 kB (corresponds to approximately 25000 readings)
  • Has an overload of 50 hPa
  • Has a direct zeroing feature of display values from pressure probes
  • Its integrated pressure sensor reads flow velocities of +1 to +20 m/s
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About CLIN

Cleanroom Industries Sdn. Bhd. was founded in 1999 as a pioneer manufacturer in Malaysia specializing in design and manufacture of a full range of cleanroom-related architectural products for cleanroom applications up to Class 1 cleanliness.

Awards & Recognitions

ISO 9001 Malaysia Power Brand Super Excellent Brand Sirim QAS Made in Malaysia Asia Pacific International Honesty Enterprise Keris Award