bgelb0
Member
- Location
- Mountain View, CA, USA
Hello -
I am using an Extech CT70 outlet / circuit load tester to investigate some missing/poor grounding in my house.
The Extech device provides an impedance measurement (in ohms) for each of the hot, neutral and ground contacts of an outlet. I am trying to figure out what it actually measures and how the measurement is achieved.
manual: www.extech.com/resources/CT70_UM.pdf (see pg 8)
I'm imagining the impedance measurement should correspond to the resistance of the branch circuit wiring, however I don't really understand how its possible to come up with an isolated measurement for each of the ground, neutral and hot conductors. For example, the device could determine an equivalent resistance based on Vdrop measurements with load applied to hot/neutral, but I don't know how it would determine how much drop occurred on one conductor vs. the other.
The documentation didn't seem to offer any clues.
Any further insight from this forum on what exactly the device is supposed to be measuring and how it is producing the measurement?
I am using an Extech CT70 outlet / circuit load tester to investigate some missing/poor grounding in my house.
The Extech device provides an impedance measurement (in ohms) for each of the hot, neutral and ground contacts of an outlet. I am trying to figure out what it actually measures and how the measurement is achieved.
manual: www.extech.com/resources/CT70_UM.pdf (see pg 8)
I'm imagining the impedance measurement should correspond to the resistance of the branch circuit wiring, however I don't really understand how its possible to come up with an isolated measurement for each of the ground, neutral and hot conductors. For example, the device could determine an equivalent resistance based on Vdrop measurements with load applied to hot/neutral, but I don't know how it would determine how much drop occurred on one conductor vs. the other.
The documentation didn't seem to offer any clues.
Any further insight from this forum on what exactly the device is supposed to be measuring and how it is producing the measurement?