strømmålere

Strømmålere are devices that measure electrical current in a circuit. They are used in electrical installations, industrial plants and energy metering to monitor how much current flows at a given point, often as part of a larger measurement or protection system. Modern strømmålere may provide real-time current values, limit values and, in many cases, data suitable for monitoring and billing.

There are several types based on how they measure current. Direct-measurement meters use a low-value shunt resistor to produce a voltage proportional to the current flowing through the circuit; this is common for lower currents. Indirect methods rely on current transformers (CTs) to scale large currents down to a safe level for measurement equipment. Hall-effect sensors can measure current without direct contact and work for both AC and DC, providing a voltage signal proportional to the current. Clamp meters are a portable, non-contact variant that measure current by sensing the magnetic field around a conductor.

Performance characteristics include accuracy, dynamic range and response time. Accuracy classes (for example 0.5% or 1%) indicate how closely the measured current matches the true value. Many strømmålere also compute derived quantities such as RMS current, phase angle, and sometimes power and energy, especially in digital or smart meters. Ranges can span from milliamps to thousands of amperes, depending on the type.

Safety and installation considerations are important; installation should follow electrical codes and proper isolation techniques. Devices may require isolation, proper burden on CTs and correct shunt values to avoid measurement errors or overload.

In modern grids and buildings, smart strømmålere enable remote reading, data logging and integration with energy-management systems for improved efficiency and demand response.