... voltage range of a chart recorder or SCADA analoginput is 1 to 5 V. A 250 Ω resistor is required to convert a 4 to 20 mA signal into a 1 to 5 V signal.Another benefit of the 4 to 20 mA current ... some cases, flow alarms can be signaled by the particle counter via the computer data collection system. A. DIAGNOSTIC SIGNALS, ALARMS, AND DISPLAYS The most common alarm found on particle ... LLC AUXILIARY FEATURES 97 A second method maintains a constant sample time, but varies the number ofparticles counted. For instance, on low-concentration filtered waters, every particle may...