FAQs - Monitoring System Buyers Guide

An environmental monitoring system is a combination of a monitoring base unit, plug-in sensors, detectors, and converters and alert notification features which can include email, SMS text, phone calls, SNMP and machine2machine (M2M) protocols including MQTT and MODBUS.

Electronic devices including computers, servers, storage and network devices give off heat. To counter this computer and server rooms, and data centres use cooling solutions including air conditioners, computer room air handlers, liquid and free cooling to maintain their IT facilities with the ASHRAE guidelines and recommendations (typically 18-25°C).

A typical server rack draws about 1-3kW in power and this equates to 1-3kW of heat output. In data centres server racks can be loaded with more power hungry servers with IT and heat loads rinsing to 5-30kW or more. If the cooling system fails, the room will see a sudden rise in temperature. Within a server rack, a loss of cooling can lead to the build-up of potential hot-spots and present a fire risk.

Monitoring the air moisture content within a server room or data centre is also important. The cooling system will be set to provide a certain airflow, at specific temperature and humidity level. Any change to the humidity level can indicate a problem with the cooling system or that water has entered the facility, either through a leaking HVAC system or flooding. Too low a humidity level can also be a problem as dry-air can present the opportunity for static build-up. High humidity can lead to mould and corrosion.

It is therefore important to monitor at least temperature in a 24/7 I environment and ideally both temperature and humidity.

There are two ways to monitor for water leakage. The first is to use a ‘Spot’ detector. This sensor is placed the position where there could be water leakage or accumulation. An example would be the overflow tray of an air conditioner or CRAC unit, or above or under a server cabinet. A Spot detector will only monitor for water (and other liquids) in a single location. When the water hits the sensor, a signal is sent to the monitoring base unit and a preset notification is issued.

The second way is to use water leakage detection rope. This type of water leakage sensor is used to monitor a perimeter area, under a raised access floor, around a room perimeter or server cabinet or in a suspended ceiling.

As with the Spot detector, as soon as water comes into contact with the opt, a signal is sent to the monitoring base unit and a preset notification is issued. A special type of water leakage detection rope is a Locate type. This sensor has zones and can report where along a length of rope the water was detected. Useful for large, hidden and potentially hard to access areas.

The first question to answer when selecting a monitoring system is ‘how many environmental parameters’ do I want to monitor, and which are the most important. The top 3 factors to monitor a temperature, humidity and water leakage.

If you only want to monitor temperature for example, you need a monitoring device with a built-in or connected temperature sensor or a device with at least 1 sensor port for a plug-in sensor. The AKCP SP1+ or HW Group STE2-Lite devices both have connected sensor and provide 1 additional port which could be useful if you wanted to add additional sensors in the future.

Separate humidity sensors are available but the most common way is to use a combined plug-in temperature & humidity sensor. For this you need a monitoring base unit with at least one port. This assumes monitoring in only one location. This can be suitable for a single server rack but in rooms with multiple racks, you may want to monitor multiple points. This would lead to the need to install monitoring base units (1 in each location/server rack) or a single base device with sufficient ports for all the plug-in sensors. Suitable devices with multiple sensor ports include the STE2-R2, Perseus 140-155 and SensorProbe+ (SPX4, SPX4, SPX16) devices.

Water leakage sensors will only require a plug-on port to connect to on the monitoring device. In a single location this means where you want to monitor temperature, humidity and water leakage you will need at least 3 sensor ports.

Dry contacts are also known as volt-free contacts or potential-free contacts are devices that switch to generate a signal but don’t have any power sources connected to them. They are either normally closed (NC) or normally open (NO).

Systems with dry contacts can be set to generate a signal when there is a change of state. An example would be a smoke or fire detector activating or door fitted with contacts, opening or closing.
Contacts such as these provide digital inputs (DI) which can be connected to a monitoring base unit. A signal is received; the monitoring device will record this and take a preset action.

Some monitoring base units also have digital outputs (DO). These can be used to provide a signal to a third-party system for it to take action. This is a form of machine logic, and an example would be to sound an alarm or flash a beacon if there is a physical security event such as a break-into a room or building.

Monitoring software is made available as part of the product or system you purchase. The software may be licensed and supplied free of charge or with an annual charge. The software may be supplied from the manufacturer’s website for download or as part of a Cloud-base application which you access once you have created an account.

Most manufacturers also provide HTTP/HTTPS access via web browser and additional locate and setup software from their websites. For example, once you have installed your device onto a local area network (LAN) you will need to know the IP-address of the device to put into a browser. Locate software or functions within monitoring applications can automatically detect base units and show their IP address and MAC ID.

Alert notifications are the messages you receive when an alarm has been raised. For most sensors the first thing to do is to set up the range for normal operation and then to set the levels at which you want alert notifications to be issued.

The actual alert notification will be configurable in terms of the message method (email, SMS txt, phone call etc) and the distribution list which will typically be via email. SMS text messaging and phone call options will be available if the function is provided within the monitoring system.

To setup the process is normally easy to do and part of the monitoring software.