Share to: It is our eyes that are capable of detecting a portion of the electromagnetic (EM) spectrum called visible light, or the optical spectrum.We describe the different frequencie â¦ s by color, with red being the lowest of the frequencies we can see.t is our eyes that are capable of detecting a portion of the electromagnetic (EM) spectrum called visible light, or the optical spectrum.
Young dogs can react unpredictably to electric dog fences, so understanding a puppy's development is essential to deciding when to start training the animal with the fence and collar. Generally, puppies should not be introduced to electric dog fences until they're at least four or five months old.
1 For example, Zareba Fence Systems estimates that materials for a temporary, 2-strand, 14-gauge electric fence costs $0.08 a foot or $408 per mile, and a permanent 6-strand high-tensile electric fence costs $0.29 a foot or $1,517 a mile. An electric fence should be tested routinely for voltage drops that indicate problems with the fence. 2  A digital voltage meter typically costs $5-$30. 3  EquiSearch.com lists tips for selecting and installing an electric fence.