DISPLAY UNIT CM7291 (Bluetooth®)

Multi-functional Receiving and Display Unit to Use Right on the Field or Output to Advanced Recorder or Logger

Hioki clamp on meters are best-in-class measuring devices incorporating Hioki’s expertise in current sensing technology. The CM7291 is the wireless receiving/display and output unit for the CT7600 and CT7700 AC/DC Current Sensor series, creating a standalone clamp meter for field use or enabling waveform signals to be output to a Hioki memory recorder or logger for further analysis.

Key Features

  • Send measured values to a smartphone or tablet using Bluetooth® wireless technology
  • Use the GENNECT Cross dedicated app to display and review measured values and waveforms in real time
  • Power supply and signal output for Current Sensor CT7000 series
  • Simultaneous dual display of the measured values, frequency, and output rate
  • Four output formats to output data to loggers or other devices (via Display Unit)
  • Supports AC adapter, AA alkaline batteries, and external power supply

Model No. (Order Code)

CM7291 For the CT7000 series, with built-in Bluetooth(R) wireless technology
Note: CM7290, CM7291 cannot be used alone. Use with CT7000 series. When used in combination with the CT7000 sensor series, the frequency band for current display and waveform output is narrower than the sensor band. *Android, Google Play and the Google Play logo are trademarks of Google Inc. *iOS is a registered trademark of Cisco Technology, Inc. and/or its affiliates in the United States and certain other countries. *iPhone, iPad, iPad mini, iPad Pro and iPod touch are trademarks of Apple Inc. *Apple and the Apple logo are trademarks of Apple Inc. App Store is a service mark of Apple Inc. *Microsoft, Windows, Windows Vista, and Excel are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. *Company names and Product names appearing in this catalog are trademarks or registered trademarks of various companies. *The Bluetooth® word mark and logos are registered trademarks owned by Bluetooth SIG, Inc. and any use of such marks by HIOKI E.E. CORPORATION is under license. *For the latest information about countries and regions where wireless operation is currently supported, please see the "Specifications" tab.

Data can be downloaded to tablets and smartphones using Hioki’s dedicated free app "GENNECT Cross," available from the Google Play or App Store.

Connect to Recorders, Data loggers, and Oscilloscopes

By connecting an AC/DC current sensor to the Display Unit CM7291, and then the system to a data logger or Memory HiCorder, you can output:

• A DC or AC (up to 5 kHz/10 kHz) current waveform as-is (using WAVE mode for waveform output)
• An analog signal generated by converting the input waveform to a series of RMS values (using RMS mode for RMS output)
• An analog signal generated by detecting the current waveform’s peak value (using PEAK mode for peak output
• An analog waveform generated by detecting the frequency of the current waveform (using FREQ mode for frequency output)

Choose from 13 different sensors

Select from an extensive lineup of sensors designed for various applications. AC/DC auto-zero current sensors are ideal for long-term recording.

Instantly create reports by a free app (GENNECT Cross)

Send measurement data to a smartphone or tablet using Bluetooth® wireless technology and use the GENNECT Cross dedicated app to display and review measured values and waveforms in real time.
The software provides a range of functionality that helps manage data in the field, including photographing measurement sites, placing measurement results on photographs, and saving hand written memos.

Click here for details about GENNECT Cross

Application: Record the amount of current generated by solar panels over the span of 1 week

System:
Display Unit CM7291
AC/DC Auto-zero Current Sensor CT7731
Output Cord L9095
Memory HiCorder MR8870

Auto-Zero Current Sensor Functionality (Current Measurement Using an AC/DC Current Sensor)

Because temperature variations cause the zero-point to shift when using a conventional DC current sensor to measure DC current, it is necessary to perform zero-adjustment periodically when recording data over an extended period of time with such a sensor. This shortcoming is caused by the effects of the Hall element that conventional DC current sensors use to to detect current. Hioki’s new auto-zero current sensors incorporate a new switching-based offset cancellation circuit developed to address this problem. The new design minimizes zero-point shift, making it possible to record DC current values over an extended period of time without the need for periodic zero-adjustment.

WAVE Waveform Output Function (Current Measurement Using an AC/DC Current Sensor)

The Display Unit CM7291 converts the current waveform for current flowing in a wire to which an AC/DC current sensor has been applied to a proportional voltage signal. By inputting that signal to a digital oscilloscope or Memory HiCorder, you can measure instantaneous AC or DC current waveforms such as a motor’s starting current waveform. Alternatively, by using the CM7291’s WAVE waveform output function in combination with a data logger, you can observe the DC current generated by a PV system’s solar panels over extended periods of time. Auto-zero current sensors are ideally suited to applications in which a DC current must be observed over an extended period of time.

RMS Mode for RMS Output (Current Measurement Using an AC/DC Current Sensor)

In this mode, the Display Unit CM7291 converts the current waveform for current flowing in a wire to which an AC/DC current sensor has been applied to a series of RMS values. It then outputs the result as a voltage signal (FAST: 45 Hz or greater, NORMAL: 10 Hz or greater, SLOW: 3 Hz or greater). This configuration is ideally suited to applications such as AC current measurement on the power supply side of a welding machine, which is characterized by abrupt current fluctuations, or long-term measurement of RMS values for the current waveform from an inverter operating at varying frequencies or a machine tool’s spindle motor.

PEAK Mode for Peak Output (Current Measurement Using an AC/DC Current Sensor)

In this mode, the Display Unit CM7291 detects the peak value of the current waveform for current flowing in a wire to which an AC/DC current sensor has been applied at the rate of 2 kS/s (= 500 μs). It then outputs its absolute value as a voltage signal with an output refresh time of 0.02 s (FAST), 0.2 s (NORMAL), or 1 s (SLOW). This configuration is ideally suited to applications in which the maximum current value of a rapidly fluctuating power supply line or load must be continuously recorded.

FREQ Mode for Frequency Output (Current Measurement Using an AC/DC Current Sensor)

In this mode, the Display Unit CM7291 calculates the frequency of the current waveform for current flowing in a wire to which an AC/DC current sensor has been applied at the user-specified interval. It then outputs the result as a voltage signal with an output refresh time of 0.2 s (FAST), 0.2 s (NORMAL), or 3 s (SLOW). In this configuration, the CM7290 can be used in applications such as frequency fluctuation inspections and testing of compressors and motors.

Basic specifications

Accuracy guaranteed: 3 years
Sensor CT7642, 7742 CT7636, 7736 CT7631, 7731
Measurement parameters DC, AC, DC+AC, Hz
Crest factor 3 at 5000 count or 2.5 at 6000 count for AC and DC+AC
Output method WAVE, RMS, PEAK, FREQ
Input connectors HIOKI PL 14
Output update time PEAK--- FAST: 0.02 s / NORMAL: 0.2 s / SLOW: 1 s
FREQ--- FAST: FAST: 0.2 s / NORMAL: 0.2 s / SLOW: 3.0 s
(WAVE, RMS: analog output)
PEAK sensing duration 2 ms or greater
(during PEAK MAX/PEAK MIN and PEAK output)
Other functions Auto range, Zero adjustment at power-up, Analysis display, Filter, Output amplification, Display value hold, Backlight , Auto-power save, Save settings, keypad lock
Typical accuracy
(WAVE output DC)
±2.0% rdg. ±10.8 mV
(60.00 A range)
±2.5% rdg. ±30.8 mV
(60.00 A range)
±1.5% rdg. ±5.8 mV
(60.00 A range)
Typical accuracy
(RMS output AC)
±2.3% rdg. ±10.8 mV
(60.00 A range)
±2.8% rdg. ±30.8 mV
(60.00 A range)
±1.8% rdg. ±5.8 mV
(60.00 A range)
Communication interface Built in Bluetooth® 4.0 LE, Display of measured values on an iOS or Android handset (CM7291 only)
Power supply LR6 alkaline batteries (AA) ×2, Continuous use: 16 h (backlight OFF and WAVE or RMS output, when used with CT7600s), Rated power 2.5 VA
or AC adapter 9445-02/03 (100 to 240V AC), or 5 to 15 V DC external power supply, Rated power 2.5 VA
Dust and water resistance (*1) IP54 (with sensor connected and caps fitted to AC adapter and power connector)
Dimensions and mass 52 mm (2.05 in)W × 163 mm (6.42 in)H × 37 mm (1.46 in)D, 220 g (7.8 oz) (including protector and battery)
Included accessories LR6 alkaline batteries ×2, Protector ×1, Instruction manual ×1
  • *1:Waterproof characteristics intended to maintain measurement function; measuring energized parts while instrument is wet will increase risk of electric shock.

Countries and regions where wireless operation is currently supported (CM7291)

Last update: August 2022
Countries and regions where wireless operation is currently supported Australia, Austria, Bangladesh, Belgium, Bulgaria, Canada, Chile, Colombia, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hong Kong, Hungary, Iceland, Ireland, Israel, Italy, Japan, Kenya, Korea, Latvia, Liechtenstein, Lithuania, Luxembourg, Macao, Malta, Myanmar, Netherlands, New Caledonia, New Zealand, Norway, Peru, Poland, Portugal, Romania, Saudi Arabia, Singapore, Slovakia, Slovenia, Spain, Sweden, Switzerland, Thailand, Turkey, United Kingdom, United States, Viet Nam
Note Use of devices that emit radio radiation requires approval in the country of use. Thus, use of the instrument in a country or region where they have not been approved may be subject to penalty as a violation of law.

Connectable sensor 2 (4)

Output cord (3)

Extension cable (7)

Other options (4)


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