Update: 30 September, 2023
The BS407 is a dedicated instrument for accurate measurement of low resistances, with a best resolution of 1 µΩ. Most multimeters offer a best resolution that is at least one thousand poorer than this. A very high resolution multimeter may attempt to resolve fairly low resistances, but it does so by resolving extremely low voltages (typically one nano-volt per micro-ohm), making it subject to severe errors from thermal emf effects and noise. In contrast, the BS407 generates sufficient test voltage across the unknown resistance to combat noise and reduce thermal emf effects to manageable levels. Current reversal can then be used to eliminate any remaining thermal offset. The BS407 uses a four terminal measurement system via high quality Kelvin Clip leads (supplied). For speed and convenience front panel switches are provided for current diversion (allowing in-situ zero adjustment) and current reversal (for identifying thermal emf errors). An LED indicator warns of open circuit leads thus preventing spurious results from being recorded. The BS407 is a fully portable instrument which operates from NiMh rechargeable batteries. The battery charger is built into the instrument and can be operated continuously during bench use. The BS407 has eight push-button selected decade measurement ranges from 1.999 mΩ up to 19.99 kΩ.
File format: PDF
Size: -
MD5 Checksum: C4CFB76D88129584FC031EEABAF4D48B
Publication date: 04 May, 2012
Downloads: -
PDF Link: TTI (THURLBY THANDAR INSTRUMENTS) BS407 Wide range precision micro-ohmmeter handbook PDF