Digital multimeter BM857s TRMS (AC+DC) 20kHz, USB/RS232 102020

Application and Key Features in Industry

This advanced measuring instrument is designed for environments where precision and safety are priorities, such as industrial automation, power distribution, or electromechanical equipment servicing. Thanks to True RMS technology with a bandwidth up to 20 kHz (in AC and AC+DC modes), the device effectively handles measurements in circuits with distorted waveforms, which is crucial when analyzing systems controlled by inverters or switching power supplies. Whether the user is an installer looking for a quick diagnostic tool or an engineer needing data for reports, the meter offers a wide measurement range: voltage up to 1000 V and current up to 20 A, covering most typical tasks in low and medium voltage installations.

It is worth noting the unique Beep-Jack™ function, which actively protects against operational errors. This system emits a sound and blocks the measurement if the leads are connected to the wrong sockets (e.g., attempting to measure voltage with leads inserted into the current sockets). This simple yet highly effective solution minimizes the risk of device damage and electric shock to the operator during live work. Additionally, the built-in process control loop measurement function (4-20 mA) with percentage (%) display allows for quick sensor calibration without the need for additional converters.

Data Display and Communication

Readability of results is key to efficient work here. The device is equipped with a dual LCD display with a resolution of up to 500,000 counts (in basic mode) and an additional bargraf operating at 60 Hz. Such a setup allows for simultaneous observation of the exact numerical value and rapid signal changes in real-time – e.g., while searching for interference or voltage oscillations. Fast sampling (5 times per second for LCD) ensures smooth reading even with dynamically changing network parameters.

For data archiving and trend analysis, the meter offers a range of advanced recording modes:

• CREST-MAX (PEAK HOLD) – recording of peak values lasting up to 0.8 ms, which is essential for detecting short overvoltages.
• MAX/MIN/MAX-MIN/AVG – automatic tracking of extreme average values in a given measurement cycle.
• Δ (Delta) Mode – the ability to compare the current reading with a reference value (so-called zero offset).

Communication with a computer is via USB or RS232 ports (optional KIT BRUA-85xa set required), which facilitates the integration of the measurement system with analytical software or SCADA systems. This means data does not need to be manually transcribed, eliminating human errors when creating technical documentation.

Safety and Resistance to External Conditions

Work in an industrial environment requires equipment resistant to overloads and surges. This model meets rigorous safety standards:

• Safety Category CAT IV 600V and CAT III 1000V – allows for safe measurements directly at the power source (e.g., on main distribution boards).
• Surge protection reaching 8 kV ensures the durability of electronics even in the event of sudden voltage spikes in the network.

Furthermore, the device features automatic range selection (Auto Range), which speeds up work with unknown signal values. The set also includes standard diagnostic functions such as continuity test, diode test, capacitance measurement up to 9999 μF, and frequency measurement up to 200 kHz. Thus, one instrument replaces several simpler meters, simplifying the toolset needed for comprehensive diagnostics of electrical and electronic installations.

In practice, this means that for industrial automation engineers, True RMS measurements up to 20 kHz are crucial, eliminating errors when analyzing inverters. In power service, the high safety category CAT IV 600V protects the operator during work on main distribution boards. Process diagnostics gain speed thanks to the percentage function for 4-20 mA current, accelerating sensor calibration without additional equipment. Meanwhile, interference analysis becomes possible thanks to peak recording (Peak Hold), which captures even short-lived overvoltages lasting fractions of a second. The fast bargraf and large display further facilitate team collaboration during