Temperature and humidity sensors give a server room or equipment closet an early warning before conditions damage anything: rack-mounted sensor probes that report into environmental monitoring systems, and standalone sensors for spaces without a full monitoring appliance already in place. By the time equipment itself reports a problem from heat or moisture, the damage has usually already started; these sensors catch it earlier.
Placement decides accuracy more than the sensor model does - mount sensors at equipment air-intake height, not just anywhere convenient in the room, since heat and humidity are not uniform across a rack or a room. Confirm the sensor's reporting method (network, dry contact, or proprietary bus) matches the monitoring system or console it must feed. For unattended or remote sites, sensors that can trigger an alert are worth more than ones that only log. COLAMCO supplies environmental sensors for the server rooms and equipment closets business, government, and education organizations monitor remotely.