OTC Tools OTC 3820-06 Perception/Vision Low Amp Probe. OTC Tools. Allows the Perception and Vision II scopes and DAT Multimeters to measure currents, both AC and DC, from 0 to 60 amps. Potential applications include: fuel injectors and fuel pump current measurements. By hooking up to the fuel pump, for instance, you can look at its mechanical integrity in a real life situation as it is running on the car. You do not need to remove the pump unnecessarily. Observe parasitic draw which can cause battery discharge, without disconnecting any leads. Measures current range: 0-60 amps AC/DC Email for product availability.