BS407 Precision Micro Ohmmeter
Ref: BS407
£762.00 £685.80 excl. VAT £822.96 inc. VATHigh basic accuracy of 0.1%
Wide range of 1µ Ohm to 20k Ohm
Current reversal switch for detecting thermal emf effects
Current diversion switch for easy zero-ing
Four terminal measurement using Kelvin clip leads
Battery operation with built-in charger
20mV clamp for ‘dry circuit’ testing
The BS407 is an instrument which is fully optimised for the task of accurate measurement of low resistances with a best resolution of 1µOhm.
Most multimeters offer a best resolution which 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.