• ZES ZIMMER LMG670 1 to 7 Channel Power Analyzer
  • ZES ZIMMER LMG670 1 to 7 Channel Power Analyzer

ZES ZIMMER LMG670 1 to 7 Channel Power Analyzer

Model : LMG670 Precision Power Analyzer

LMG670 - Power Analysis²

One-shot Results for Narrowband, Full Spectrum and Harmonics


Measurement Channels

  • Outstanding accuracy of 0.015% of measured value + 0.01% of range
  • Full dynamic range of 500 µA to 32 A / 3 mV to 1000 V per channel available in single instrument
  • Power measurements from standby to full load (max. 32 A) without mechanical changes
  • Analog bandwidth DC up to 10 MHz
  • Modular configuration with 1 to 7 power measurement channels (alternatively 6 channels + 1 I/O card)
  • Gapless sampling up to 18 bit and a minimal cycle time of 30 ms
  • Delay time between V and I input < 3ns, very precise measurements at small power factors (PF) and/or high frequencies


  • Simultaneous measurement of narrow- and broadband values through innovative DualPath architecture
  • Simultaneous capturing of fundamental frequency and broadband RMS values for instantaneous detection of losses, resp. high-frequency components
  • Harmonics and interharmonics up to 2000. order, as required by EN61000-4-7
  • With optional I/O card speed/torque inputs freely configurable for all signal types (analogue, frequency as RS422,TTL or HTL) via menu
  • Flexible scripting tool for custom applications
  • Simultaneous measurement of V, I, P values and harmonics, presentation in tabular or graphical form
  • Signal filters freely configurable by frequency, type and characteristics
  • Synchronization to up to 7 different frequencies simultaneously
  • Flicker measurement, interactions between grid and appliance according to EN61000-4-15


  • Large and clearly arranged touchscreen GUI for intuitive handling
  • All instrument features displayed, identical look-and-feel for local and remote operation for quick and easy familiarization

Memory and Interfaces

  • Internal storage of long-term measurements even with shortest cycle-time thanks to integrated mass storage device
  • Excellent connectivity via USB2.0, Gbit-LAN, RS-232 and DVI/VGA


  • Convenient "plug-and-measure" through automated sensor detection
  • no external sensor power supply required
  • 12 months guaranteed calibration interval for minimal service cost and optimal availability
  • Calibration certificate included free-of-charge in first delivery
  • 24 months warranty

Technical Specifications





LMG670 (Table top)

433 mm

177 mm

590 mm

LMG670 (Rack)

84 HP

4 RU

590 mm




Depending on installed options: max. 18.5 kg

Protection class

EN 61010 (IEC 61010, VDE 0411), protection class I / IP20 in accordance with EN 60529

Electromagnetic compatibility

EN 61326


0 ... 40 °C (operation) / -20 ... 50 °C (storage)

Climatic category

Normal environmental conditions according to EN 61010

Line input

100 ... 230 V, 47 ... 63 Hz, max. 400 W


Simultaneous measurement in two bandwidths thanks DualPath - no compromises, no doubt

In Power meters of traditional construction, a signal first passes through an analog processing, the output values are digitized by an A / D converter and then processed. The resulting signal may then either measured over the full range, or treated with anti-aliasing filters, e.g., to serve as the basis for an FFT or other digital filtering. By restriction to an A / D converter, one has to taken certain disadvantages into account. If measured with a filter, in order to avoid aliasing in the FFT, the broadband values are lost. When the filter is disengaged, strictly speaking, the FFT has to be omitted. If the FFT is performed without anti-aliasing filter for measurement over the full bandwidth, the quality of the calculated values is questionable. For example, an aliasing error of 50% would of course be easily detected, a deviation of 0.5% could remain unnoticed. Finally, it can be switched back and forth between measurements with and without filters. The validity of these results is, however, also doubtful, as would be expected of a temporal invariability of the signal, which is hardly ever the case in reality. Moreover, this method is extremely time consuming.


Ultimately, the shown measurement methods are unsatisfactory compromises. For this reason, ZES ZIMMER has radically redesigned the signal conditioning and developed the DualPath architecture. The analog side corresponds to the conventional instruments, the subsequent digital processing, however, was revolutionized. The power analyzers of the LMG600 Series are the first power meters featuring two A / D converters in each of the two independent signal paths for current and voltage channel. A filter for the contact measurement of the broadband signal, and another for the narrowband signal at the output of anti-aliasing filter. By means of parallel processing of the digitized samples, the user has access to both measurements of the same signal without the risk of aliasing. This unique process eliminates all the disadvantages of previous approaches and guarantees accurate results in the shortest time.

The right channel combination for every application

Configuration with 1 to 7 power measuring channels (alternatively 6 measuring channels and Process-Signal-Interface)
Retrofitting of channels available!


Power measurements on inverter / motor combination
with DC


Power measurements on inverter / motor combination 


Inverter with DC link
1-phase Input
3-phase Output


Inverter measurements
1-phase Input
3-phase Output


power measurement
of 3-phase motors


Efficiency measurement
of power supplies


Measuring of core losses

For every application the right channel type:

  • A-Channel: 0.025 % accuracy, up to 10 MHz
  • B-Channel: 0.07 % accuracy, up to 500 kHz
  • C-Channel: 0.04 % accuracy, up to 10 kHz


Inductive Components and Magnetic Cores

In the ferromagnetic components of an electrical machine, core losses result from the influence of varying magnetic fields, caused by both, constant magnetic reversal and eddy current losses, which are ultimately converted into heat or sound energy. The total losses are frequency dependent and should be minimized wherever possible, as they have a strong impact on the range of the batteries in , electric vehicles, for example. With the exciting current of a test winding and the magnetizing voltage of a sensor winding, the core power loss can be measured directly. The magnetic flux density in the core material can be derived from the rectified value of the current induced in the sensor winding. The magnetic field strength is proportional to the current flowing in the test winding. While the high-frequency currents can be measured directly in the magnetic cores, high-precision transducers are being used to measure the high amperage of laminated cores.

Solid and Laminated Magnetic Cores

Ultra-high-speed Machines

Two Challenges

Loss minimization in ultra-high-speed machines

Ultra-high-speed motors allow for very high power densities. However, this also results in small cooling surfaces. Therefore, a reduction of losses is even more important at high speed.

Measuring with high bandwidth and accuracy

Ultra-high-speed electrical drive systems and high inverter switching frequencies require high bandwidth AND high accuracy in the power measurement.

Measuring Converter and Motor Power and Efficiency

Measuring Converter and Motor Power and Efficiency

Measuring Converter and Motor Power and Efficiency_2

Electric drive systems

More than half of the electrical energy generated worldwide is converted into mechanical motion, and the importance of electrical drives for transport and movement is growing steadily. While outdated speed controllers are afflicted with losses of up to 40 %, modern, frequency-controlled systems can achieve efficiency levels of over 95 %. These are frequency converters that use pulse width modulation to control the speed of the motor with hardly any losses. The objective is to optimally adjust the converter and motor to one-another, in order to achieve as high an overall efficiency as possible. Simultaneously measuring the input power, the intermediate circuit, and the output power of the converter as well as the mechanical power given out by the motor is anything but trivial. In addition to the integration of sensor technology (wideband current sensors for high currents, if necessary voltage divider, precise speed
and torque transmitters), the device must meet the challenge of measuring the very steep-flanked signals at the converter output. This environment is often described as harsh, not merely from a EMC point of view.

Electric Drive Systems 1

Of course the key question in the analysis of electrical drive systems is: which part of the electrical energy at the converter output relates to the torque-relevant basic frequency of the motor, and which part to the remaining frequency range, particularly the harmonic spectrum? To give an accurate answer, it has long been necessary to perform two separate measuring procedures: one measurement without filters to establish the wide-band power and another
measurement of a filtered signal to determine the power at certain frequencies or a subsequent FFT analysis to measure the harmonic spectrum.

Electric Drive Systems 2

On the one hand, this procedure was time-consuming, and on the other hand, it could not always be assumed that exactly the same conditions were present during the second measurement, as in the first.
The innovative DualPath architecture of the LMG670 provides all of the required results simultaneously in a single measurement, with maximum precision, and the widest frequency range on the market – free from aliasing effects.

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