Group3 manufactures a range of precision magnetic field measuring instruments. Based on Hall Effect sensors, but accurately corrected for temperature, and non-linearity of the Hall element, to give the most accurate Hall probe instruments available. Temperature drift is less than 10ppm/degree C, overall system accuracy of 0.01%, with 1:600,000 resolution
Note the specification of 0.01% - that is for the measuring system - probe plus instrument, over 0 to 50 degrees C. The DTM-151 is many times more accurate than competing teslameters - read the spec. sheets carefully!
A new model has just been launched - the Group3 DTM-151, featuring enhanced resolution - down to 0.0000001T (=0.001 G) . The model also has many new design features to make it much more immune to disturbance by electrical transients. Filters, suppression, and isolation components have been added, making it suitable to be used in extremely noisy installations such as ion implanters.
Several models of the instrument are available, and several probe types are manufactured to give a choice of physical size, accuracy and price.
Probes are individually calibrated and corrected for temperature and field non-linearities. Multi-range probes allow different full scale readings to be made without changing probes. Standard full scale ranges are 0.3T, 0.6T, 1.2T, 3T.
Remote readings by computer are available via serial communications ( RS232 and serial fiber optics) or GPIB/IEEE488 communications.
The instrument is housed in a small free standing bench case, with panel mount bezels and mounting kits available.
Models of instrument available:
Enhanced noise immunity - , increased resolution. High precision instrument, 0.01% accuracy, 1 in 600,000 resolution, fully temperature compensated.
High Resolution, no temperature compensation, 0.03% accuracy at 25 deg c, 1:600,000 resolution
Economy model instrument, with enhanced transient immunity, 0.03% accuracy at 25 deg c, no temperature compensation, 1:6,000 resolution
Probes of varying length can be ordered - minimum 2 metres, maximum 30 metres. Available as shielded or unshielded cables.
Models of probe available:
Standard transverse probe. Probe head approx. 14mm x 14mm. Sensitive area within probe head approx. 1.6 x 4.0 mm. Available as standard or high sensitivity versions, and at various precision ratings.
Miniature probe. Probe head 5mm x 14 mm. sensitive area 0.5 x 1.0mm. Available as standard or high sensitivity, and at various precision ratings.
Probe Holders.
A range of probe holders are available - transverse, axial, and specially manufactured holders such as a triple probe holder for three axis measurements.
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A new analog output Hall probe, corrected for temperature and linearity.