What is a Smart Meter and How Does it Work

Keep an eye on how much power you’re using with one of these clever gauges.

Electricity meters come in two varieties: the DIY approach or the fixed meter that is installed by your electricity supplier.

Using the DIY approach the meter monitors your electricity usage via a sensor that clips onto the main electricity cable usually located in your meter cupboard. This sensor has a wireless transmitter that sends your electricity usage data to the display unit, which can be positioned anywhere in your home.

Meters directly connected to your electricity supply operate in much the same way as the DIY variety, but they are wired directly into your power supply.

Most meters use radio frequency (RF) transmitters in the 900MHz ISM (industrial, scientific and medical) band that is reserved for special radio transmissions as well as systems like Bluetooth, though some utilize the 2.4GHz and 5.8GHz bands. The RF enables your reading to be sent to the supplier.

Smart meters send your readings to your electricity company in about 45 seconds, once a day. Some meters can also be read with portable handheld devices, but you no longer have to be home when a reading is due.

Inside the REX2 Smart Meter

LCD screen – To give some immediate data about power usage, an LCD screen is used attached via a ZEBRA connector.

Security sealed – Tampering with electricity meters is illegal. The meter’s outer case has a security seal that must not be broken for the device to stay valid.

Main integrated circuits – The meter consists of a system chip, LCD driver and an amplifier IC that, together, allow the meter to read and transmit your electrical usage.

Power supply – The smart meter needs a power supply. The thick copper wires enable the meter to be plugged directly into your home’s mains.

Current transformer – The meter can’t directly measure electrical usage; instead it uses a current transformer that sends power consumption information to the meter’s electronics.