Introduction
In any electrical system, some circuit paths require very low resistance, such as a closed switch or a lightning protection system, it must allow the electrical current to flow freely in order for the system to function properly. For example, if a contact point between metal parts of a lightning protection system is improperly welded, it might not be able to achieve the designed purpose of the system, since it could lead to a significant increase in resistance. Therefore it is crucial to assess the quality or the conditions of these paths.
Problem
Assessing the electrical conductivity of a low resistance system.
Solution
The S460+ Microhmeteris one of the most accurate instruments for low resistance testing. It can be used to deduce the condition of contacts between conductor parts and the length or quality of wires. Simply clamp on to the conjoining metals, and based on whether the readings show a high or low resistance value, users will be able to deduce the bonding quality (Figure 1).
Difficulties
The surface of some metals, such as iron when it is corroded or rusted it can decrease the conductivity and result in an OL reading. In these situations, users must remove the rust layer before conducting another measurement (Figure 2, 3).
Benefits
- 4 terminal – highly accurate 1.5% accuracy
- Resolution: 0.01mΩ
- Range: 0.01mΩ～100kΩ ; 0.01mΩ～100Ω
- Wire length measurement
