What is a Current Sensor and Current Transducer?

Posted on Wednesday May 27, 2020 at 05:42PM  


Current Sensors (CS) and Current Transducers (CTs) are used to monitor the current flowing through an electrical conductor. They generate the information needed for status and metering applications. Though people tend to use the terms ‘current sensor’ and ‘CT’ interchangeably, there are some more than subtle differences between the two terms.

So, what exactly is the difference between a Current Sensor and a Current Transducer?

Let’s start by defining the most general of all the terms: Current Sensor.


What is a Current Sensor?

A Current Sensor is a device that senses and measures the flow of electrons, or current flow. Current sensors can be digital (switch) or analog. 

How Does a Current Sensor Work?

A digital current sensor reads the current flowing through the conductor and uses an on/off switch to display communicate whether the current is running at the predetermined amperage set by the user. The switch can be used to control a warning light or trigger a relay to send a message to another alarm or system.  A Current Switch is integrated with normally open (NO) or normally closed (NC) switch. At a preset current level (trip point) the switch will either open or close. 

An analog current sensor displays the range or volume consumed, much like a speedometer in a car, and can also be used to trigger the same light, data output, etc. Whether you choose digital or analog depends on your project needs. 

Applications: Current sensors are perfect for monitoring fans, pumps, motors, and other electrical loads for proper operation. 

Example: Imagine you manage an underground mine and need to ensure a certain level of airflow reaches the miners working below. Your engineers have determined that a 17amp flow will generate enough breathable air for the miners. You attach a current sensor to a controller on the wall of the mine to measure the amount of air flow. If the air flow sits at 17amp, your digital switch will stay on or your analog will maintain a steady number. If the air flow goes below 17amp, an alarm will sound. 

Unit Vent Heater Control Wiring Diagram

What is a Current Transducer?

A Current Transducer is a device that converts alternating or direct electrical signals into a proportional industrial standard electrical signal. 

What does a Current Transducer do?

A current transducer reads current and generates a signal for its output.  In this case, current is sensed and converted (transduced) into a proportional output (milli-amp or voltage). Output types include:  4 – 20mA, 0 – 5Vdc, 0 – 10Vdc, 1Vac, or 0.333Vac. The output range can then be interpreted by software to produce a current reading.

Applications: Current transducers also help keep track of load trending, motor control, and fan/pump status.

Veris offers a variety of current sensors, current transducers, and current transformers in both split-core and solid-core options. To learn more about our current sensing products, visit our website or call to speak with our sales team at 1-800-354-8556 or +1 503.598.4564.

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