Multifunction Meter: Types, Working and its Applications

• 2023-08-15

Continuing our series of articles illustrating the importance of knowing what and how various control instruments function, we bring you multifunction energy meters this time.

A Multifunction Meter or MFM is basically used for monitoring electrical installations.

It monitors and measures several electrical parameters like voltage, current, active power, reactive power, apparent power, power factor, active energy, phase angle, harmonic distortion, etc.

Hence the name multifunction, meaning serving multiple functions.

What is a Multifunction Meter?

As previously discussed, multifunction meters are electrical devices installed in complex systems to measure and monitor parameters.

It is usually involved in systems that require a precise value of electricity consistently.

Apart from monitoring, it can also track energy consumption, cut unnecessary costs and troubleshoot a multitude of electrical mishaps.

The biggest advantage of a multifunction meter is it can measure three phases at the same time.

History of Multifunction Meter

First invented during the early 1920s, multifunction meters were mostly in the form of radio receivers and vacuum tube electronic devices then.

The first multifunction meter was invented by Donald Macadie. He was dissatisfied with carrying separate instruments for maintaining the telecommunication circuits.

That was his motivation for inventing a unique instrument that can measure volts, ohms, and amperes.

At that time, the multifunction meter was known as Avometer. This meter comprised voltage and precision resistors, sockets and switches for selecting ranges and a moving coil meter.

Working principle of a Multifunction Meter

Unlike popular belief, the working principle of a multifunction meter is very different from that of a traditional induction meter.

A multifunction meter is much more 'intelligent' in comparison. It samples user power supply voltage and current in real-time and then uses a special electronic circuit including a microcontroller to process the sampled voltage and current signals.

This is then converted into electrical energy. The pulse output (when provided) is proportional to the final processed signals (kWh units).

How does a Multifunction Meter work?

In order to properly function, a multifunction meter has many electrical components, each serving a different purpose:

Sensors

Potential and current transformers are commonly used to measure voltage and electric current.

The current transformer (CT) has a primary winding with usually a single turn (or wire/cable) passing through a ferromagnetic core (of soft iron).

Based on Faraday's law of induction, the current flowing through the cable will create a magnetic field which is then detected in the secondary winding of the ring core.

This way, there is no need to open the power circuit in order to measure the current.

Data managers

In order to collect the information recorded by the sensors, data managers are used.

It collects the calculated parameters and sends them through the RS-845 interface (the standard interface for physical communication) to the display.

Some data managers can read up to 96 sensors, with 96 single-phase, 48 biphasic, or 32 three-phase circuit breakers.

What industries use multifunction meters?

Multifunction meters are widely used in the industry sector across India and the world.

As the mass production cost of manufacture of such MFM has come down drastically, many uses of MFM have subsequently developed.

As it principally is for cutting back on costs by monitoring and tracking energy consumption, it stands out as a necessary instrument.

It also takes the backup of other integrated parameters. Some locations it is famously used in are:

1. Motor control centers
2. Control panels
3. Genset panels
4. Power distribution panels

How to pick the right multifunction meter?

Now, coming to the question of the hour, how to choose the right multimeter for your system.

What factors should be considered? What specifications should you be on the lookout for?

Here are some tips to ease your journey:

1. Understand the functionality of a multifunction meter
2. Identify the critical parameters to be monitored
3. Identify the types of output required
4. Identify power supply (single or three phase)

Properly understanding the model you're considering investing in and whether it meets what you intended for it to do is extremely vital.

It might seem elementary at first glance, but the gaps in knowledge ofte0n lead to dissatisfaction later on.

That's where Multispan's MFM-13 comes into the picture. With an elegant display and a wide measuring range, it is the perfect meter for any industrial application - be it plastics, chemicals, food and beverage, energy, pharmaceuticals, petrochemicals, etc.

It has an accuracy class of 0.5. It also has optional features like pulse output and RS-485 Modbus communication.

Some advantages that set MFM-13 apart from other multifunction meters:

• Readings can be taken locally or by centralized or remote systems
• Has an internal memory for storing recorded values
• Programmable outputs
• Great reading accuracy
• Cost optimization
• Centralization of other inputs
• In-built event log memory
• Easy to maintain and upkeep
• Simple user interface
• Has two modes: manual and auto
• Elegant, user-friendly display

Combining the best features, MFM-13 has been designed with your best interests in mind.

It is a straightforward device that showcases all these qualities and more. Moreover, it assures user safety and durability.

Still got any queries? For further information, feel free to contact us

Frequently Asked Questions

How accurate is a multifunction meter?

Accuracy is specified according to each model design.
MFM has an accuracy class of 0.5, meaning 0.5% on power and energy parameters.

What is a three-phase multifunction meter?

The most suitable for industrial and commercial applications, a three-phase multifunction meter is a device that measures and monitors energy consumption in three-phase systems. It measures all electrical parameters like voltage, current and power simultaneously.

What are the uses of the multifunction meter?

As discussed previously, multifunction meters have applications across various industries. They can be used as bench instruments or hand-held devices as per the current setup demands. Hand-held is apt for basic fault findings while bench is preferred for a high degree of accuracy.

What is the difference between a trivector meter and a multifunction meter?

The main difference between a trivector meter and a multifunction meter is that the former is comparatively more versatile. It can be configured for different CT settings as required whereas a multifunction meter has fixed CT settings.

What are the dimensions of a multifunction meter?

The dimensions of a multifunction meter may differ depending on the model design. The optimal dimensions are 96x96mm, but do pick depending on what fits your current needs. MFM has dimensions of 96x96mm too.