An auditor must set the Sensitivity of an E-Meter exactly right for each pc.
The setting is different for almost every pc.
Too low a Sensitivity on some pcs (like Sens 5-32) will obscure reads and make them look like ticks. It will obscure an F/N. Whereas a Sens 16-128 will show reads and F/Ns.
A pc can be hindered by the auditor not setting the Sensitivity high enough to show reads and F/Ns. Items are missed as well as F/Ns.
When auditing a flying pc or a Clear or OT the auditor who sets the Sensitivity too high gets weird impressions of the case.
"Latent reads" on such a case are common. They aren't latent at all. What happens is that the F/N is more than a dial wide at high Sensitivity and a started F/N looks like a read as its sweep is stopped by the pin on the right of the dial.
In this way uncharged items are taken up, the case is slowed, overrun and general upsets requiring repairs occur.
On one hand electrode an OT VII sometimes has a ¾ dial wide F/N at Sens 5-32.
This would mean a ¾ dial F/N at Sens 2-32 with two cans.
A Clear sometimes has a floating TA at Sens 32-32 instead of an F/N. He would have to be run at Sens 3-32 two cans to keep him on a dial or detect F/Ns.
This is a very important matter as the auditor will miss F/Ns, think beginning F/Ns are reads and as the Pre-OT is off the dial, miss reads.
Thus uncharged areas are run and charged ones are missed.
The result is very chaotic to repair.
Some lower level pcs also have a need for lower Sensitivity settings.
Sometimes an easy pc looks very difficult just because of wrong Sensitivity settings.
Set the Sensitivity for the pc for a half dial F/N maximum or minimum.
Don't get repairs.