Omega RD-87 Series is a precision strip chart recorder for recording temperature, AC Voltage, AC Current, 4 — 20ma loops and DC Voltage. It features a digital display, alarm functions, user selectable delays times, and low power isolated (dry) relay contacts. The alarm can be set to sound an audible signal when the measurement has exceeded an upper or lower limit. Each limit is individually set from the front panel. A delay time before the alarm is activated may be set by the user to prevent nuisance alarms.