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FAQ

FAQ-mp001: What is the SENIS magnetic field sensing technology?

Our magnetic field sensing probes contain one of the following magnetic sensors:

a. Hall Effect devices, either discrete or integrated on a silicon chip - for magnetic fields from 1µT to 20T, DC to a frequency over 75kHz

b. Anisotropic Magneto-Resistors (AMR) - for magnetic fields from 1nT to 100µT

c. Inductive coils – for any magnetic field, at frequency from 10kHz to over 500kHz

Each of these devices is combined with biasing and signal conditioning electronic circuits. Some of Hall-effect probes incorporate a part of the associated electronics.

FAQ-mp002: What is the SENIS 3D (3-axis) Hall probe technology (integrated/discrete)?

a. Fully integrated Hall Probes: The best-on-the-market horizontal and vertical Hall elements, temperature sensor and pre-amplifiers & electronic circuit for offset & noise canceling integrated on a single Si-chip

b. Integrated Hall Probes: The best-on-the-market horizontal and vertical Hall elements and temperature sensor integrated on a single Si-chip

c. Hybrid Hall Probes: High-resolution (very low-noise) discrete Hall sensors and temperature sensor integrated in the Hall probe

See: http://www.senis.ch/magnetic/hall-probes/overview-hall-probes

FAQ-mp003: What is the difference between Magnetic Field Transducers and Teslameters/Gaussmeters?

a. A Magnetic Field Transducer is an instrument that provides at its output a convenient-level voltage, proportional to the measured magnetic field.

b. A Digital Teslameter, or in short Teslameter or Gaussmeter, incorporates a magnetic field transducer, analog-to-digital converter, and display, which shows the numerical value of the measured magnetic field

See http://www.senis.ch/magnetic/magnetic-measurement-products

FAQ-mp004: What is the spatial resolution of SENIS Hall probes?

a. Fully integrated Hall Probes: Total magnetic field sensitive volume (sensitive area): 140µm x 140 µm x 10µm; Bx & Bz: 140µm x 140µm x 10µm; By: 20µm x 20µm x 5µm

b. Integrated Hall Probes: 100µm x 100 µm x 10µm; Bx & Bz: 100µm x 100µm x 10µm; By: 45µm x 45µm x 10µm

c. Hybrid Hall Probes: 150µm x 150 µm x 1µm for each Hall element

See http://www.senis.ch/magnetic/a... and http://www.senis.ch/docs/default-source/datasheet-hall-probe/magnetic-field-transducer-types.pdf?sfvrsn=0

FAQ-mp005: What is the minimal thickness of SENIS Hall probe (for air gap magnetic field measurement)?

a. Fully integrated Hall Probes: Ceramic packaging: <250µm; Hall chip: 50µm

b. Integrated Hall Probes: Ceramic packaging: <250µm; Hall chip: 50µm

c. Hybrid Hall Probes: 0.4mm

See: http://www.senis.ch/magnetic/hall-probes/integrated-hall-probes and http://www.senis.ch/magnetic/hall-probes/hybrid-hall-probes

FAQ-mp006: Are SENIS probes temperature-compensated?

Yes. A temperature sensor integrated besides the Hall sensors is used for temperature compensation of the Hall probe offset and sensitivity.

FAQ-mt001: What is the magnetic field resolution of SENIS devices?

a. Measurement instruments with fully integrated Hall Probes: Transducer: ±50µT @2T / Teslameter: ±50ppm

b. Measurement instruments with integrated Hall Probes: Transducer: ±5µT @2T / Teslameter: ±50ppm

c. Measurement instruments with hybrid Hall Probes: Transducer: ±3µT @2T / Teslameter: ±2ppm

See http://www.senis.ch/magnetic/analog-magnetic-field-transducers/overview-magnetic-transducers and http://www.senis.ch/docs/default-source/datasheet-hall-probe/magnetic-field-transducer-types.pdf?sfvrsn=0

FAQ-mt002: What is the accuracy of the magnetic field measurement of SENIS devices?

a. Measurement instruments with fully integrated Hall Probes: Transducer: ±0.1% / Teslameter: 0.05%

b. Measurement instruments with integrated Hall Probes: Transducer: ±0.1% / Teslameter: 0.05%

c. Measurement instruments with hybrid Hall Probes: Transducer: ±0.01% / Teslameter: 0.002%

See http://www.senis.ch/magnetic/analog-magnetic-field-transducers/overview-magnetic-transducers and http://www.senis.ch/docs/default-source/datasheet-hall-probe/magnetic-field-transducer-types.pdf?sfvrsn=0

FAQ-mt003: What is the noise level (noise spectral density) of SENIS devices?

a. Measurement instruments with fully integrated Hall Probes: Single-axis: 1/f noise: 1µT/√Hz @ 200mT; white noise: 0.3µT/√Hz @ 200mT; Corner frequency: 10Hz
Three-axis: 1/f noise: 2µT/√Hz @ 200mT; white noise: 0.8µT/√Hz @ 200mT; Corner frequency: 5Hz

b. Measurement instruments with integrated Hall Probes: 1/f noise: 0.09µT/√Hz @ 200mT; white noise: depends on f-bandwidth; Corner frequency: 10Hz

c. Measurement instruments with hybrid Hall Probes: 1/f noise: 0.02µT/√Hz @ 200mT; white noise: 0.016µT/√Hz @ 200mT; Corner frequency: 10Hz

See http://www.senis.ch/magnetic/analog-magnetic-field-transducers/overview-magnetic-transducers and http://www.senis.ch/docs/default-source/datasheet-hall-probe/magnetic-field-transducer-types.pdf?sfvrsn=0

FAQ-mt004: What is the frequency bandwidth (3dB)?

a. With fully integrated Hall Probes: Single-axis: 25kHz / Three axis: 75kHz

b. With integrated Hall Probes: 4kHz; High-frequency version available: 500kHz

c. With hybrid Hall Probes: 4kHz

See http://www.senis.ch/magnetic/analog-magnetic-field-transducers/overview-magnetic-transducers and http://www.senis.ch/docs/default-source/datasheet-hall-probe/magnetic-field-transducer-types.pdf?sfvrsn=0

FAQ-mt005: Is the SENIS electronic module (Transducer/Teslameter) temperature-compensated?

Yes, The in-electronic-box temperature sensor measures is used for compensation of the electronic module of a SENIS measurement instrument.

FAQ-mt006: What is the highest magnetic field that can be measured?

SENIS’ magnetic field measurement instruments allow measuring of the magnetic fields from few µT up to 30T. The standard measurement ranges are 20mT, 200mT, 3T and 20T.

FAQ-mm001: What are the main features of SENIS Magnetic Field Mapper/Scanner?

a. Magnetic Field Mapping System allows users to perform a fast, high resolution mapping of magnetic field around an electromagnet or permanent magnet. It is used for development of magnetic systems and as a reliable Quality assessment tool in production.

b. Magnetic Field Scanner measures all three components of the magnetic field in a single point. The high-performance, low-noise SENIS integrated 3D Hall probes are utilized.

c. Magnetic Field Scanner can measure inhomogeneity of the magnetic field, number of poles in a multi-pole permanent magnet, pole displacement, etc.

d. It can be also used as an easy-to-use coordinate measurement machine (CMM) for dimensional measurement of object under test and for magnet absolute positioning.

e. The map of the magnetic field can be presented in the form of color coded 2D or 3D isometric visual display on a PC screen, or as a table of numerical values of the magnetic field, etc.

See: http://www.senis.ch/magnetic/magnetic-field-scanner/overview-magnetic-field-scanner

FAQ-mm002: What is the positioning accuracy of SENIS Magnetic Field Mapper/Scanner?

a. For the linear axes (X, Y and Z) the positioning resolution/accuracy/repeatability of ±1µm is achieved through the utilization of the optical linear encoders.

b. For the rotary stage the positioning resolution/accuracy/ repeatability of ±0.022° is achieved through the utilization of the incremental rotary encoders.

FAQ-mm003: What is the spatial resolution of magnetic field measurement?

a. Fully integrated Hall Probes: Total magnetic field sensitive volume (sensitive area): 140µm x 140 µm x 10µm; Bx & Bz: 140µm x 140µm x 10µm; By: 20µm x 20µm x 5µm

b. Integrated Hall Probes: 100µm x 100 µm x 10µm; Bx & Bz: 100µm x 100µm x 10µm; By: 45µm x 45µm x 10µm

FAQ-mm004: Can AC Magnetic Field be mapped by SENIS Magnetic Field Mapper?

Yes, the magnetic field from DC to 25kHz can be mapped with the standard mapper version.
There is a Magnetic Field Mapper version for mapping the High-Frequency magnetic fields of up to 500kHz.

FAQ-mm005: What does the SENIS Mapper use a touch sensor for?

a. A Touch Sensor (also Tactile Sensor) prevents a Hall probe from a mechanical damage. It serves as an emergency stop provision, which is triggered whenever an object is touched by the probe during the measurement process.

b. Optionally, the touch sensor can also be used for the dimensional measurement of objects under test and for their absolute positioning (CMM).

FAQ-mm006: What is the magnetic field measurement accuracy of SENIS Magnetic Field Mapper/Scanner?

The Accuracy of the magnetic field measurement is better than 0.1%.The magnetic fields from few µT to 20T can be measured.

Q cs001: What is the SENIS electric current sensing technology?

SENIS provides open- and closed-loop current sensors with and without magnetic core (fix- and split core, i.e. clamp-on). All SENIS current sensors are contact-less and based on the magnetic field measurement around current carrying conductors. The magnetic field sensing devices utilized in our current sensors are Hall Effect devices (either discrete or integrated on a silicon chip) or Anisotropic Magneto-Resistors (AMR).

a. CS-03 Current Sensor series are miniature low current, high accuracy and high sensitivity sensors, with high voltage isolation capability. Sensors of CS-03 Series are PCB mount current sensors with a magnetic shield and high performance linear effect Hall IC.

b. BBM-02 BusBar Current Module consists of two magnetic field sensors on each side of an electric current Bus Bar. Two precision Hall Effect IC’s sense the magnetic field as a function of current on both sides of the Bus Bar. This enables effective cancellation of external magnetic fields without magnetic cores or shielding which can give rise to non-linearity and hysteresis effects.

c. CTH Clamp-on Closed-loop Current Transducers are utilized for measurement of DC, AC and pulsed currents, with the galvanic isolation between the primary circuit and the secondary circuit. The CTH transducer consists of two parts: transducer head and transducer electronics, connected with the multi-paired shielded cable of up to 10m length. For the elimination of the remanent magnetic field in the split-cores, the CTH-100 utilizes an advanced degaussing (demagnetization) process.

d. Clamp-on DC Open-loop MicroAmmeter can measure the absolute value of DC currents, or the difference of two DC currents, in the range of 10A to 10mA, without cutting off the current carrying conductor(s). The front-end of the MicroAmmeter is a clamp-on toroidal ferro-magnetic core with an air gap, in which the Hall elements of a differential Hall magnetometer is inserted. The magnetic core increases the sensitivity and nearly eliminates the external magnetic field influence on the current measurement.

Q cs002: What is the measurement range of SENIS current sensors?

a. CS-03 Current Sensors: DC 0.1A, 0.2A,0.25A, 2A, 2.5A, 8A, 15A and 25A
b. BBM-02 BusBar Current Modules: DC/AC 200A – 20kA
c. CTH Clamp-on Current Transducers: 100A – 10kA
d. Clamp-on DC MicroAmmeter: DC 10A to 10mA

Q cs003: What is the accuracy of the SENIS current sensors?

a. CS-03 Current Sensors: <2%
b. BBM-02 BusBar Current Modules: <1%
c. CTH Clamp-on Current Transducers: <0.1%
d. Clamp-on DC MicroAmmeter: <10%

Q cs004: What is the resolution of the SENIS current sensors?

a. CS-03 Current Sensors: <0.05%
b. BBM-02 BusBar Current Modules: <1%
c. CTH Clamp-on Current Transducers: <0.05%
d. Clamp-on DC MicroAmmeter: <1uA

Q cs005: What is the frequency bandwidth of SENIS current sensors

a. CS-03 Current Sensors: DC – 7kHz
b. BBM-02 BusBar Current Modules: DC - 200kHz
c. CTH Clamp-on Current Transducers: DC – 300kHz
d. Clamp-on DC MicroAmmeter: DC – 1Hz

FAQ-mc001: What calibration and characterization does SENIS provide?

FAQ-mc001: What calibration and characterization does SENIS provide?

a. DC calibration for the magnetic field measurement instruments:

  • Output vs magnetic field
  • Output vs magnetic field and temperature

b. AC calibration for the magnetic field measurement instruments – small-signal frequency response

c. Hall probe sensing axes angular calibration

d. Hall probe magnetic field sensitive volume calibration (precise definition of the Hall probe sensitive area location)

e. Noise measurement of Hall probes

See: http://www.senis.ch/support/test-calibration-consulting/calibration-characterization

FAQ-mc002: How do you perform the calibration DC of Hall probes?

The result of the “Output vs magnetic field” DC calibration is a table which shows the actual values of the teslameter output reading, or the output voltage of the magnetic transducer, for a number of DC magnetic field intensities, at room temperature of the probe and electronic module.

DC calibration may include temperature dependences of offset and transduction constant of a measurement instrument. The result of such “Output vs magnetic field and temperature” DC calibration is a table which shows the actual values of the teslameter output reading, or the output voltage of the magnetic transducer, for a number of DC magnetic field intensities and probe temperatures, at room temperature of the electronic module.

See: http://www.senis.ch/support/test-calibration-consulting/calibration-characterization

FAQ-mc003: What is the calibrated DC magnetic field range?

a. Low magnetic fields: from 1µT to 45mT;
Calibration equipment: calibrated Helmholtz coils, ammeter, Voltmeter

b. Medium magnetic fields: from 43mT to 2.1T;
Calibration equipment: iron-core electromagnet, NMR teslameter, Voltmeter

c. Higher magnetic fields: from 2T to 9T;
Calibration equipment: Calibrated superconducting magnet, ammeter, voltmeter

d. High magnetic fields: from 9T to 20T;
Calibration equipment: Calibrated superconducting magnet, ammeter, voltmeter

FAQ-mc004: What is the DC calibration accuracy?

a. When using a calibrated coil: up to 0.01% of the measured value, or up to offset fluctuation of the instrument under calibration (whatever is greater)

b. When using the NMR Teslameter: 30ppm of the measured value, or up to offset fluctuation of the instrument under calibration (whatever is greater)

FAQ-mc005: What is the calibration temperature?

a. Standard calibration temperature for “Output vs magnetic field” calibration: 20°C ± 3°C (room temperature)

b. Standard calibration temperatures for “Output vs magnetic field and temperature” calibration: 20°C ± 10°C

c. Optionally, offset and low magnetic field calibration can be performed in the temperature range from -40°C to 160°C.

FAQ-mc006: How do you perform the calibration AC of Hall probes?

AC calibration provides information about the actual small-signal frequency response of a magnetic measurement instrument. The calibration results are given as plots and tables, which show the actual values of the teslameter output reading, or the output voltage of the magnetic transducer, for a reference AC magnetic field with an amplitude of a few mT, at a number of frequencies, at room temperature of the probe and electronic module. The measurement results are presented as Complex Magnetic Sensitivity vs Frequency and as Bode plots of the tested instrument.

See: http://www.senis.ch/support/test-calibration-consulting/calibration-characterization

FAQ mc007: What are conditions and equipment for AC calibration?

a. Max amplitude of the periodic magnetic field used for calibration: 10mT

b. Frequency range: DC to 1MHz

c. Calibration temperature: 20°C ±3°C

d. Optionally, AC calibration can be performed in the temperature range from -40°C to 160°

FAQ-mc008: What is the recommended calibration period of SENIS Hall probes?

The recommended calibration period (calibration at SENIS laboratory): 12 months.