Tech Progress: How Science Can Save Energy and Lives
The ability to measure electrical currents is important in the optimizing the efficiency of the electrical system, as well as safety reasons. Recent advances in sensor technology allow engineers to measure currents in smaller increments than in the past.
Sensor Safety
A sensor that malfunctions can be a fire hazard. Sensors must be tested to make certain that they perform as intended. They must meet domestic standards for use in the US, and they must meet the standards of the receiving country in the case of exports.
There are several different testing agencies in the United States. They include the American National Standards Institute (ANSI), Underwriters Laboratories (UL), and CSA International. Sensors that have not been tested by a certifying agency should not be used, as there are no means to assure that they will work properly.
Choosing the Right Sensor
The first consideration in choosing the right sensor is to locate one that will measure the currents in an appropriate range for the intended use. There are in-line sensors available, and some that clip on the outside wire.
Sensors are available in both open-loop and closed-loop types. Open-loop sensors are more appropriate when it is possible that the sensor will have to withstand overloads. Closed-loop sensors provide quicker response times and produce less noise than open-loop sensors.
Hall Effect Sensors
Hall effect sensors from places like Aim Dynamics measure loads as low as 20 microamps. The sensor works by passing the current conductor through a magnetically permeable core. This concentrates the conductor’s magnetic field. When energized, it can measure small changes in current.
Many companies have a number of Hall effect sensors available that can be used in a wide array of projects. Some even offer a range of high accuracy, DC current sensors.
Other Considerations
Other considerations that must be taken into account when purchasing a sensor is their response time, accuracy, type of mounting, and operating temperature range. It is important to consider the outside dimensions of the device to make certain that it fits the given application.
As one can see, there are many considerations that must be noted when choosing a sensor for your application. There is a wide range of sensors available today and it is almost certain that you will find one that meets your needs, regardless of the size of current that needs to be measured.