Wireless Temperature and Humidity Sensors: Creating an Environmental Lab Monitoring System

What do microbial growth, product spoilage, and poorly performing equipment all have in common? They are all losses sustained at the hands of two invisible culprits—unexpected temperature and humidity changes.

Anyone in the life sciences industry knows this battle well, especially when it comes to cold storage monitoring. Food, medicine, vaccines, biosamples, and more rely on fixed temperature and humidity conditions to remain preserved.

Consider this recent study on the effects of ventilation, humidity, and temperature on bacterial growth. The researchers found that good ventilation and reduced humidity can significantly reduce the growth of bacteria, especially under 70% relative humidity (RH). High temperatures increased bacterial growth, but proper ventilation diminished this effect.

This research emphasizes the significance of monitoring humidity and temperature to minimize bacterial growth. The results can guide the creation of improved storage solutions and preservation methods for laboratory settings.

Although labs have tightly controlled HVAC systems, extra humidity can still creep in. If humidity is higher than 65%, experiment results can be impacted. For example, scientists often weigh samples or powders on a balance. It is important to record these weights in grams carefully, often to the thousandth or or ten thousandth grams to ensure accuracy. If humidity is too high, water vapor from the air can be absorbed into the powder and change the weight. If you are running experiments throughout the year and the lab’s humidity fluctuates from very dry to very muggy, the weight of your samples or powders fluctuate, causing variations in the experiment and providing inconsistent results.

This potential fallout is why wireless sensors are the indispensable sidekicks of professionals tasked with overseeing sensitive environmental parameters. Wireless sensors, combined with a high-quality monitoring platform, allow facilities to track temperature, light, humidity, and other crucial lab vital signs. And with today’s remote monitoring technology, teams can now check this data from anywhere and at any time!

What are the types of temperature monitoring sensors?

Let’s start with temperature, one of the key ambient factors to monitor in a laboratory. The following are the main sensors one can expect to see in the temperature monitoring market. Keep in mind that not all of these tools are created equal, and some of them do not support remote monitoring.

Feel the heat: manual logging with thermometers

Although thermometers have come a long way from mercury-filled glass tubes, they are still limited to measuring the current temperature only. This classic temperature measurement method requires frequent and regular human intervention to create a log of readings, so remote monitoring isn’t an option. Basic thermometers and human readings may seem like a cost-effective monitoring solution upfront, but the numerous personnel hours spent on logging data will get expensive over time. Besides, no one likes tediously writing down temperatures in a log book.

Old-school vibes: mechanical chart recorders

Chart recorders are a step up from thermometers in the evolution of temperature monitoring. These innovative-for-their-time sensors record readings by automatically passing a pen over a strip of paper. They’re similar to seismographs, but instead of measuring earthquakes, they measure temperature changes and other ambient variables like pressure, pH, and humidity.

While chart recorders reduce the amount of human involvement needed, they unfortunately don’t offer remote monitoring capabilities. So if a lab heats up to undesirable temperatures in the middle of the night, the chart recorders will document it—but no one will know about it until someone manually checks the recorder the next day. At that point, it may be too late to save valuable lab assets.

Embracing the future: data loggers

Data loggers brought environmental monitoring into the modern era. These devices can continuously record anything that translates to electrical signals, from extreme temperatures to carbon dioxide levels. A large memory capacity allows data loggers to store temperature readings for several months or even years. Data loggers are also a solution for those wondering how to monitor temperature remotely without WiFi, as loggers can store data on a USB memory device instead of a local network.

One of the most common smart temperature sensor types on data loggers is the thermocouple, which measures temperature by detecting the voltage generated between two different metals when heated. The hotter the metal, the greater the voltage output, which the thermocouple uses to calculate temperature. It's a clever way to turn heat energy into something measurable and understandable.

However, data loggers are usually not equipped to alert users remotely of any abnormalities or provide data access via a cloud setting. For situations where immediate action may be required, like in biotech labs or pharmaceutical facilities—this simply won’t do.

Cut the cords: wireless digital sensors

No more stumbling over wires or pining for more electrical outlets—wireless digital temperature sensors are now all the rage. In fact, experts predict that the global market for wireless temperature sensors will grow from 16.06 million units in 2020 to 24.93 million units by 2026.

These sensors convert readings into electrical signals and transmit them via a WiFi temperature monitor or another wireless protocol. Teams can access this information from anywhere, boosting productivity and increasing confidence in asset stability. Remote temperature monitoring via a cell phone is even possible with this technology.

Another major perk of wireless digital sensors is the ease of installation without drilling access holes or screw mounts. Sensor models like the Element A contain a strong magnet, making installation on metallic surfaces even simpler. Users can just as easily install the lightweight Element A with double-sided Velcro on non-metallic surfaces.

How can I monitor temperature remotely?

Remote temperature monitoring requires two main tools—digital temperature sensors and a remote monitoring system. The sensors are connected to a base station or gateway that communicates data to a cloud-based platform, allowing teams to access temperature data remotely.

A cloud-based temperature monitoring platform serves to connect all of a facility’s temperature sensors into a centralized dashboard, revealing new opportunities and areas for improvement. The Elemental Machines platform is a prime example, with features like:

Precise climate monitoring from -200°C to 200°C
24/7 monitoring and alerting via SMS, voice, app, and email alerts
Predictive analytics using advanced machine learning techniques to understand abnormal behavior and anticipate maintenance needs
Insights on equipment usage, machine health, and operating environments
Electronic record-keeping for quality assurance and regulatory compliance
Compatibility with existing assets, Electronic Lab Notebooks (ELN), laboratory information management systems (LIMS), and quality management systems (QMS)

Now, let’s move on to another vital metric that facilities must track—humidity.

How can I monitor humidity remotely?

Monitoring humidity remotely requires installing moisture sensors and implementing a remote monitoring system. Simply place humidity sensors in the area to be monitored, and they will transmit data regarding moisture levels to a remote monitoring system. Personnel can then access this data from their laptop, smartphone, or tablet, no matter how close or far they are from the monitored area.

Like temperature monitoring, the humidity monitoring market includes chart recorders, data loggers, wireless sensors, and cloud-based monitoring systems. The sensor technology is different, however, and the three most common sensor types include the following:

Capacitive sensors - Capacitive humidity sensors use a strip of metal oxide between two electrodes to measure the amount of moisture in the air. The metal oxide's electrical capacity changes as it absorbs or releases water molecules from the surrounding air, which depends on the humidity level. When humidity increases, the electrical charge between the two plates changes, and the device uses these changes to calculate humidity levels.
Resistive sensors - Resistive humidity sensors measure the resistance of a material that changes as the surrounding air's moisture content changes. As the air becomes more humid, the material's resistance decreases, and the resistance increases as the air gets drier.
Thermal conductivity sensors - Thermal conductivity humidity sensors work by heating up a small area of air and then measuring how quickly the heat is conducted away. Since the presence of water molecules affects the heat transfer rate, the humidity level can be determined by comparing the heat transfer rate to a reference gas.

The Element A is an effective solution for measuring humidity—plus, it also measures temperature, light, and pressure! It communicates all of this data to the cloud every 15 seconds via a gateway, so reviewing teams know they have the most up-to-date information.

What is the difference between a hygrometer and a humidity meter?

The terms "hygrometer" vs "humidity meter" are often used interchangeably, and both refer to devices that measure the amount of moisture present in the air. A hygrometer is a broader term that can refer to any humidity-measuring device, including those that use mechanical, electrical, or chemical principles to do so. On the other hand, a humidity meter typically refers to a digital device that measures relative humidity using electronic sensors (like the capacitive, resistive, or thermal conductivity sensors mentioned above).

So while both measure humidity, searching for “humidity meters” will likely reveal more modern, digital options.

Do cheap hygrometers work for humidity monitoring?

While cheaper hygrometers and humidity meters can work, their accuracy and reliability may be less promising. To get the most accurate readings, choose a humidity-measuring instrument that is calibrated and certified by a reputable standards organization, such as the National Institute of Standards and Technology (NIST). These will usually cost more, as someone had to spend time and resources calibrating the device to NIST standards.

At the end of the day, the best humidity sensor for a facility will depend on specific needs and budget. Will a slight rise in humidity cause the loss of millions of dollars in assets? Or are the consequences of minor humidity changes less severe? These are the kinds of questions to be asking when choosing a humidity measuring and monitoring system.

If you’re unsure about the best way to approach temperature and humidity monitoring, our team of experts at Elemental Machines is happy to help. We prepare customized remote monitoring solutions to suit each customer’s needs and budget—as they are now and as they grow!

How do you monitor room temperature and humidity?

Monitoring the temperature and humidity of an entire room versus a single container or appliance requires a different strategy. The larger the space, the more variables there are to mess with data output. Direct sunlight exposure, an odd HVAC placement, or even an unexpected power outage can skew temperature readings.

Temperature mapping is a critical monitoring practice designed to combat issues like these. The World Health Organization (WHO) has even studied various temperature mapping techniques, specifically for vaccines and pharmaceutical product cold storage. They advise that a mapping study should monitor an area for at least 48 hours to understand the environment accurately.

How might this work in practice? Let’s say a team wants to monitor their entire lab environment at large, which could look something like this:

The team places three temperature sensors in each of the four corners of the lab for 12 sensors total—one near the ceiling, one near the floor, and one halfway between the ceiling and floor in each corner. Using only one room temperature monitoring device is not enough to collect a comprehensive data set.
The team lets the sensors collect data for at least 48 hours for the temperature mapping study.
The results reveal that one side of the lab is significantly hotter than the other, and they— frustratingly—have all their lab freezers on the hot side!
After moving the freezers over to the other side of the room and letting a few months pass, the team notices the freezers' energy usage has decreased significantly, saving the team a significant amount of financial expense.

In their study, the WHO included an interesting case where a newly installed cold room was above the recommended temperature range for nearly 48 hours. The problem? A loose screw. Yes, it was truly that simple. This loose screw caused enough refrigerant to leak to the point where the unit wasn’t cooling the cold room. It was an easy fix, but without the knowledge of too-high temperatures, how long would it have taken for someone to catch this issue? And what assets might have spoiled in the meantime?

How do I make an IoT temperature sensor and humidity sensor?

Making an IoT sensor takes some engineering and programming skills—plus a whole lot of time. For a life sciences company, time is too valuable to focus on such time-consuming tasks unrelated to the company’s core proficiencies.

If one truly feels compelled to make an IoT temperature and humidity sensor from scratch, then be prepared to invest a lot of time into making sure it's effective. Consider how reliable the finished product will be compared to the high-quality IoT sensors on the market today. When an alarm goes off on the homemade version, can it be trusted? And what risks are involved with losing monitored assets if the temperature or humidity changes unexpectedly and under the radar of the homemade device?

Honestly, it’s much more sensible to purchase an IoT sensor that is already made. With the advanced capabilities of today’s IoT temperature and humidity sensors, trying to DIY your own sensor is like reinventing the wheel.

Along with temperature and humidity sensor devices, LabOps teams may wonder, “Is there a temperature and humidity sensor app to monitor all of these environmental factors?” There is, and it’s called Elemental Machines.

Elemental Machines—Taking the guesswork out of temperature and humidity monitoring

Elemental Machines makes a suite of hardware and software for all lab environment monitoring needs. With our system, facilities can easily check the humidity, temperature, light, and more of any room, all from one data-fueled dashboard.

If any readings fall out of the designated range, the team will receive immediate alerts from the Elemental Machines app. And when we say “alerts,” we don’t mean a general, panicked notice that says something like “POWER OUTAGE!” or “TEMPERATURE RISING!” Our alerts describe precisely which area is at issue, the current temperature and humidity levels, and other vital context necessary to make rapid decisions remotely.

Elemental Machines also streamlines quality assurance and regulatory compliance procedures. Should the need for a report arise, for example, users can easily download a put-together report in seconds. Our NIST-traceable sensors, audit reports, field calibration, and IQ/OQ procedures will help you establish solid compliance practices without breaking a sweat.

Ultimately, we want our customers to be comfortable and informed, whether on location or halfway around the world. From customized alerting to AI data forecasting, Elemental Machines does it all. To see “it all” in action, request a demo here!