When customers rely on you to keep their data safe and accessible around the clock, maintaining data center assets in top shape is vital to your bottom line. But it’s not just the assets themselves that need to be maintained — in a data center, environmental monitoring and adjustments matter, too.
The electronic equipment housed in data centers is extremely sensitive to temperature and humidity fluctuations. Routers, servers, and battery backups need optimal environmental conditions to run at peak performance and to avoid premature breakdowns. Smart data center managers and technicians employ sensors to constantly monitor for humidity and temperature changes, making adjustments as needed to avoid catastrophic failures.
Without proper and regular humidity calibration, data centers risk asset failure and data loss due to electrostatic discharge (ESD) or condensation. Over time, sensors lose their accuracy and need to be recalibrated to take accurate measurements. Luckily, the right calibration tools will simplify precision humidity monitoring and give you peace of mind.
This application note outlines the benefits of humidity control, recommended levels for humidity and temperature in data centers, and how humidity generators like the Fluke 5128A calibrate sensors to ensure accurate measurements.
Why Humidity Can Be Bad News for Data Centers
Both high and low humidity can cause extensive damage to data center equipment.
One of the biggest risks to electronic systems is electrostatic discharge (ESD). ESD occurs when two charged objects come in contact with each other and create a burst of electricity. ESD is more common when air is dry, since charges easily build up in environments with low humidity.
Even small electric shocks have the potential to damage electronic equipment. Technicians easily build up a static charge via mundane actions that cause friction, such as removing a sweater, adjusting their position while sitting in a fabric-coated chair, or shuffling across a carpet. Then, when they get close to a piece of equipment, this charge transfers and flows into the machine, causing irreparable damage to the sensitive electronics and even outages.
The true cost of ESD damage in the electronics industry is unknown, but experts estimate that it’s at least half a billion dollars per year. Most data center teams know these risks already, which is why they’ll invest in high-quality, anti-static equipment like mats and gloves to reduce the chances of transferring static shock. But it’s equally important to track and adjust humidity in the entire facility to further reduce the chances of equipment damage.
Besides ESD, poor humidity control also leads to problems like:
- Condensation
- Bacterial growth
- Mold
- Metal warping
- Corrosion
Once these issues happen, equipment will need to undergo extensive repairs or be replaced entirely. That’s why it pays, literally, to be aware of humidity levels and adjust them accordingly. The less time and money you have to spend on fixing existing equipment, the more you can focus on growth.
Benefits of Humidity Control
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends that data centers maintain relative humidity (RH) levels of around 60%. This general guideline pertains to most data centers, but may change based on the type of equipment operating in the facility. For example, if your data center experiences higher levels of copper and silver corrosion, ASHRAE recommends that RH should generally stay lower than 60%.
That said, every data center will have their own recommended RH range based on individual needs. You can calculate these based on a data center’s quality assurance (QA) and testing guidelines. Once you’ve determined the right humidity level for your data center, you can track RH with wall- or machine-mounted sensors and adjust humidity with equipment like humidifiers.
Over time, you can expect to see the following benefits:
- Enhanced reliability: Proper humidity levels minimize the risk of ESD and condensation, ensuring continuous and reliable operation.
- Extended equipment lifespan: Maintaining optimal humidity levels prevents corrosion and other moisture-related damage, thereby extending the lifespan of expensive hardware.
- Increased energy efficiency: Optimized RH levels contribute to the overall energy efficiency of cooling systems, reducing operational costs and environmental impact.
Temperature and Humidity:Understanding the Relationship
Humidity isn’t the only metric that matters for mitigating the risks of RSD and corrosion. It’s important to pay attention to temperature in the facility as well, since temperature and humidity have an interdependent relationship.
When the temperature increases, so does the air’s capacity to hold moisture. So humidity can get higher in hotter temperatures than in colder ones. Inversely, low temperatures mean less capacity for humidity.
This matters because heat buildup from machines is a major problem that data centers face. Equipping your facility with cooling technology to keep heat levels down is important to prevent machines from overheating — but also matters when you’re trying to control humidity. And if your data center is located in a building that experiences brutal winters or blasts the AC in the summer, ensuring thattemperatures don’t get too low can be important for keeping machines in top shape.
ASHRAE recommends keeping dry bulb temperature between 18 °C - 27 °C (64.4 °F - 80.6 °F) inside a data center. Temperatures colder than that range promote static-forming conditions, and temperatures hotter than that range encourage too much moisture build-up. Some facilities can safely operate at higher or lower temperatures than that general range, but it depends on the type of equipment your facility operates and your expectations for quality assurance. Consult specific ASHRAE or OEM guidelines to determine the best temperature limits for your facility.
The best way to ensure that humidity and temperature stay at optimal levels is to track them via sensors. However, sensors can lose accuracy over time, promoting the need for humidity calibration.
Why Calibration Matters for Humidity Control
Humidity generators like the Fluke 5128A calibrate sensors, ensuring measurements are as accurate as possible . Periodic calibration gives your team confidence in room-level humidity measurements, allowing your team to make adjustments that promote equipment longevity and decrease downtime.
The Fluke 5128A works by generating humidity and te mperature in a controlled chamber with a drier and humidifier system. The calibrator measures the difference between the humidity and temperature in the chamber vs. the device under test (DUT). The discrepancy between the calibrator and DUT measurements outlines how much the DUT needs to be adjusted in order for it to maintain humidity measurement accuracy.
The 5128A is specifically designed for room-level sensors with probes. It features a variety of benefits that make it perfect for data center humidity center calibration, such as:
- Portability: Lightweight and compact, you can place the 5128A on a cart and roll it to each sensor in the facility.
- Configurability: The calibrator allows you to measure probes in multiple ways, providing flexibility for varying sensor sizes and specifications.
- Multi-sensor testing: Test several probes at once — up to five half-inch sensors fit inside the chamber together.
- Multi-point testing: Much more accurate and thorough than a handheld humidity meter, the 5128A calibrates multiple test points at the same time.
Plus, the 5128A is designed to be easy to use and maintain, with a simple setup and calibration process.
Using the Fluke 5128A for Humidity Sensor Calibration
The 5128A’s process for calibrating humidity sensors typically involves the following steps:
- Prepare: Gather the necessary tools and accessories for calibration. Fill the humidity reservoir on the 5128A according to the manufacturer’s instructions. Verify that the measurement chamber is empty and does not contain any excess condensation.
- Gather sensors: Remove the humidity sensors from wherever they are mounted in your data center and place them in the calibrator. Depending on their size, you will either place the entire sensor inside the chamber or partially through the outside holes. Alternatively, you can roll the 5128A to the location of the sensor or DUT and test it with the 5128A without removing it from the wall, if necessary.
- Begin calibration: Choose set points for temperature and humidity that correspond with the manufacturer specifications for the DUT and program them into the calibrator. Start with lower temperature and humidity points first, then slowly ramp them up at each step of the calibration process. This ramp-up helps prevent excess moisture buildup in the chamber. However, sometimes a DUT may require that you work from high to low temperature/humidity instead, so be sure to consult manufacturer calibration instructions when possible.
- Wait: Give the chamber and DUT(s) time to stabilize.
- Measure: Record the calibrator’s temperature and humidity readings. Then, record the reading on each DUT. The discrepancy between measurement on the calibrator and DUT indicates how much the sensor will need to be adjusted in order to restore it to manufacturer specifications.
- Adjust: Make changes to the sensors to calibrate them to intended specifications. In cases of extreme temperature discrepancies, you may need to replace the sensors entirely.
- Reinstall: Place sensors back in their monitoring stations to continue tracking humidity inthe facility.
Manufacturer recommendations, environment, and use case will impact how frequently you calibrate each humidity sensor. However, if your data center is generally kept clean and dry, it’s a good rule of thumb to calibrate each humidity sensorat least once per year.
Conclusion
Regular humidity calibration saves data centers from costly outages, equipment damage, and loss of customer data. When your sensors provide accurate RH readings, your teams can maintain recommended humidity levels in the facility to ensure that machines run optimally for as long as they can. Extended equipment lifespans, increased reliability, and higher energy efficiency all result from humidity control. And fortunately, calibrating humidity sensors is fairly imple with humidity generators like the 5128A. Routine checks and adjustments keep your data center humming along while you focus on growth throughout the facility and beyond.