Instruction Manual - Sierra Instruments

Sierra Instruments Instruction ManualSmartTrak ® 100 SeriesSmartTrak FeaturesSetpoint AdjustmentThe setpoint (command) input signal you supply to SmartTrak must be a directlinear representation of 0% to 100% of the mass flow full-scale value. Apply thesetpoint signal from pin 8 to any of the analog grounds (see Chapter 2 for wiringdetails). A setpoint value of 0 VDC or mA (or 1 VDC or 4 mA) will regulate theflow to 0% and a setpoint value of 5.00 VDC (or 10 VDC or 20 mA) will adjust theflow to 100% of the instrument’s full scale range.When the setpoint (command) signal is applied, the flow controller will reach thesetpoint value within two seconds to within ±2% of the selected flow rate.CAUTION: DO NOT LEAVE A SETPOINT APPLIED FOR ANEXTENDED PERIOD OF TIME TO A CONTROLLER WHEN THEGAS SUPPLY IS SHUT OFF OR BLOCKED. Damage may result and theinstrument will become hot to the touch. Instead, see below for use of the“Valve Close” feature which allows you to disable the valve whilemaintaining the setpoint signal. This may be set by the Pilot Module, theSmartTrak Software, or an external analog signal.Changing the Output or Setpoint SignalsTo modify the analog output or setpoint signals (from 4-20mA to 0-10Vdc, forexample), you must use the Pilot Module or the SmartTrak Software. The datalabel will indicate the form these signals had when the instrument was lastcalibrated. We strongly recommend that you adapt the data label if theconfiguration is changed for future reference. See Chapter 4 or 5 for the necessaryprocedure.Over-Range ConditionIf the mass flow rate exceeds the full-scale range listed on the SmartTrak data label(see samples on page 2-1), the output signal will measure above full-scale.However, the device has not been calibrated for flows in excess of the calibratedfull scale value and the value will be both non-linear and inaccurate if an over-rangecondition exists. Please be aware that the analog outputs can exceed full scale by asmuch as 20%, or more.Once the over-range condition has been removed, it may take up to 30 seconds forthe SmartTrak to recover and resume normal operation. An over-range conditionwill not harm the instrument.24