Sensor-Mounting Best Practices: Meeting Growing Demands

Jessica Ciesla
April 27, 2021

This blog from Raritan answers the question, where best to mount environmental monitoring sensors in the rack?  From airflow to temperature, we address the highs and lows of sensor placement. 

There’s an old proverb that goes, “Trust, but verify.” This sentiment is particularly apt for data-center management, where it’s vital to track almost every data point you can get your hands on. The need for better environmental monitoring capabilities is growing to meet the demands of increasing computer, network, and storage densities, as well as the mounting criticality of operating temperature management. The quality of data center monitoring continues to improve with the production of ever-more specialized sensors, making it easier to both trust and verify the operating conditions inside your data center. But with more options, what are the best practices for mounting these sensors? 

The Highs and Lows of Sensor Placement (Literally) 

Sensor placement is a matter of understanding the purpose of the sensor and the use of the resulting data you will be receiving, both within the context of industry standards and the wisdom of best practices. Temperature and humidity sensors, for example, should be deployed in large quantities and in a variety of locations—since understanding the efficiency of your mechanical system is a big-picture exercise. Leak-detection sensors, on the other hand, should be deployed in a more targeted manner. 

Here is a shortlist of sensor types and their ideal locations: 

• Airflow sensors—measure movement of air in meters/second. Best located at perforated panels, minimum of one per aisle; also at supply and return of CRAC/CRAH. 
• Pressure sensors—measure pressure differential above and below the raised floor. Best located in targeted areas, one above and one below the same location on the floor. 
• Temperature and humidity sensors—measure degrees and RH. Per ASHRAE guidelines, position at three locations both in front of and at the back of the rack to capture Delta T. 
• Contact closure sensors—provide an alert when contact across adjoining surfaces is no longer maintained. Most commonly used on rack door entrances; can be used to monitor critical electrical and control panels. 
• Leak detection sensors—provide alerts when continuity is no longer maintained along a rope or at a sensor due to contact with liquid. Commonly located around CRACs and along the route of refrigerant piping. 

Almost by definition, best practices are ever evolving. As new monitoring challenges arise and sensor technologies are made available, the location and use of sensors at the rack and within the data center will continue to evolve. 

A Sensor for Every Need 

The variety of data center environmental monitoring sensors available from Raritan makes it easy for you to both trust and verify your operating conditions. Contact us here at Raritan to learn more about Smart Sensors and how they can deliver valuable insight into your data center.