Considerations in Automating Cleanroom Temperature Monitoring

certification_testing_mainClosely monitoring air temperature is necessary to prevent mold, bacterial agents, and other contaminants in your cleanroom. It is also important for any temperature-sensitive products and equipment. Automating your data equipment can bring accuracy and convenience to your process. What else do you need to know about making such a transformation?

Loggers and Sensors

Data loggers or recorders are used to record and store values like temperature, and include a range of software and hardware. They use sensors and other equipment to electronically track information. Models are available in portable, Ethernet, and wireless units. These loggers will accommodate both single and multi-channel systems.

The sensor you need will depend on your specific application, and the manufacturer will be able to help you determine this. The most common sensors are thermocouples. They’re easy and cost-effective, but they are not highly accurate. Semiconductors are also low-cost with accuracy similar to thermocouples. They provide an output voltage or current proportional to temperature with a limited operating range. The most accurate devices are RTDs ad thermistors, but they have a more limited operating range than thermocouples.

Wired vs Wireless

The layout of your facility will probably be the deciding factor between a wired or wireless system. There are advantages to both. Ethernet-capable devices are more affordable, and they can be mounted wherever you need to measure temperature. They can connect to both RTD and thermocouple sensors and plugged into an Ethernet port.

Wireless systems require a greater investment, but come with more bells and whistles. You’re able to access data in real-time, and with cloud-based services, you can modify system configurations from anywhere there’s an Internet connection.


Most data loggers will let you set the frequency of alarm checks so you can immediately address out-of-specification temperatures. Additionally, some models can continue to log data during power or Internet outages. If you’re connected to a cloud-based system, you can periodically check for irregularities from your smartphone any time. You can also prevent users from inadvertently modifying or deleting data by modifying access levels.

Overall, automating your temperature monitoring connects managers to their critical process and product data for an ideal environment. These systems are likely to be commonplace in the future. The right system and time for implementation will depend on your specific needs.

For questions about cleanroom certification, validation, or construction, contact Gerbig Engineering Company. We are cleanroom specialists with 30 years of experience. Your success is our priority. Call us at 888-628-0056 or email for an expert consultation.

Pharmaceutical Manufacturing: 2 Methods of Liquid Particle Counting

While liquids that are tested in pharmaceutical manufacturing are expected to be free from contamination, particles can enter as a result of handling and managing the water supply. Therefore, it is vital to measure particle contamination in these processes.

Particle counters are primarily used to test finished products, but a second and equally-important application is monitoring quality of water for injection.

Currently, two methods accomplish this: light obscuration and light scattering.

Light Obscuration

This method directs a laser through a narrow capillary tube with a flowing stream of liquid. Particles that pass through the beam will block light, casting shadows across the photo-detector. A calibrated particle counter determines the sizes of the particles based on how much light is blocked.

This method is best used to measure relatively large particles that are not quite visible to the naked eye. These fall into a range of 1.5 microns to over 150 microns.

Light Scattering

This method also directs a laser through a narrow capillary tube with a flowing stream of liquid. However, rather than cast shadows, passing particles scatter the laser beam via refraction, reflection, and diffraction. Mirrors collect the scattered light and focus it onto a photodetector to be analyzed.

Again, the amount of disruption to the beam is equivalent to the size of the particle. In this case, the more light that is scattered, the bigger the particle. Like with obscuration, known particle size standards are used to calibrate particle counters.

Light scattering is appropriate for volumetric instruments down to 0.2 µm. It’s effective up to 20 µm.

Pharmaceutical products are comprised mostly of water, especially products that are injected. Controlling the quality of this water is extremely important. For a full description of the technology and applications of liquid particle counting, see this article in Controlled Environments.

If you have questions about cleanroom certification, validation, or manufacturing, contact the experts at Gerbig Engineering Company. We are passionate about your success. Call us at 888-628-0056 or email

Pros and Cons of Cleanroom Microbe Detection Devices

Traditional methods of detecting and correcting the presence of viable particles in a cleanroom can be lengthy. If present, viable particles can result in weeks of lost manufacturing time. However, non-traditional microbe detection significantly hastens the process of detecting and correcting the presence of viable particles. As with anything, there are downsides to these options, as well. Here is a brief comparison of options.


  • Plates. Several methods use plates that are put in areas of interest (high-risk) around the cleanroom. The plates collect particles in the air for several hours. Then the plates are collected, incubated, and after colonization, identified and counted based on the surface area of the plate. This process takes 3-7 days, during which the microorganisms will only continue to grow.
  • Air samplers. This is a more active means of collection, resulting in a better sample. Filter membranes, agar strips, or contact plates are used to collect particles through impaction. It works in a way that doesn’t disrupt the normal airflow and doesn’t render biological particles non-viable. This, too, takes time to colonize and count particles, however.

Both of these methods are less expensive, but take a significant amount of time.


  • Laser particle counters. There are a variety of these on the market. The lasers cause biological particles to fluoresce as they pass through the beam. Photo-sensitive optics detect the light and count the particles. It is possible to separate the counts into viable and non-viable data. These counters don’t identify the microorganisms like the traditional methods do. Lab analysis is still required; however, these counters offer real-time monitoring. Investigation is simpler and faster, leading to earlier corrective action. In fact, it’s feasible that they can detect viables early enough to prevent an incident. The greatest down side of these counters is cost.
  • Portable microbe sensors. These, too, uses photo-sensitive optics to measure the volume of fluorescing particles. They heat up captured particles to get them to glow, so it isn’t completely in real-time, but it is close. This method does not identify viables, and there is no particle count. They are less expensive than laser particle counters, and really are best used as an early warning detection system.

When comparing methods of microbe detection, consider how long it would take to detect a breach, investigate the source, and then verify the effectiveness of remediation. If the time factor with a traditional system devastates your operation, it may be worth investing in a more sophisticated, real-time particle counter. If you have questions about cleanroom validation, certification, or manufacturing, contact Gerbig Engineering Company. We are experts with nearly 30 years of experience.  Call us at 888-628-0056 or email

Selecting the Right Pressure Monitor for your Clean Environment

Ideal cleanroom conditions rely on accurate pressure readings. Air in a controlled environment is not constant, so it’s critical to prevent pressure changes. This ensures that pressure won’t be so low as to allow contaminates in or so high as to waste energy.

When choosing an airflow monitor, your priorities are:

  • To be able to see readings at a glance
  • To fetch accurate readings
  • To catch any shift in air flow in real time
  • That all staff is confidently safe and protected

Therefore, in choosing the right monitoring system for your needs, keep the following in mind:

  1. What does it take to keep the device accurate? How many hours will staff need to spend calibrating and re-calibrating the device? Make sure the device is a high enough quality that you’re confident in the accuracy of its measurements.
  2. Fire/smoke protection. Moving from one side to the other, does the device protect against fire and/or smoke? Smoke dampers are available for through-the-wall monitoring – something that might be relevant for fire codes.
  3. Cost-effectiveness. Compare costs and features of several devices before you make your final decision. Are there other solutions that will deliver constant airflow monitoring without the bells and alarms?
  4. How challenging is installation? Who will be able to install it, what are the costs, and how much time will it take?
  5. Does the device meet all necessary requirements? For example, is it UL-approved?
  6. How else can you ensure accuracy? Measurement points should be as close as possible to the point of action. This is superior to transferring a control signal to a centralized monitoring system.

Technology is always advancing, so keep an eye open to what is new in pressure monitoring. With this in mind, you can select a monitor knowing that its functions will be relevant for a long time or with the intention to replace it every few years.

For questions about cleanroom certification, validation, or construction, contact Gerbig Engineering Company. We are cleanroom specialists with 30 years of experience. Your success is our priority. Call us at 888-628-0056 or email for an expert consultation.

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