Sierra FLAT-TRAKTM 780S - Manual (Page 10)

Chapter 1 Introduction Series 780S Instruction Manual
1-4 IM-78S-B
Smart Electronics Features
Instrument Validation
Two simple tests offer full “field-validation” of your Smart mass
flow meter. The first test checks the system electronics, linearization
and microprocessor functionality and is performed by injecting a
known input value and confirming that the flow meter outputs the
expected value. The second test verifies that the instrument’s pri-
mary sensing elements have not drifted or shifted from their original
calibration and is accomplished by measuring the resistance of the
velocity and temperature sensors and comparing the results to the
NIST-traceable calibration data provided with the flow meter. To-
gether, these tests confirm that your meter is working correctly and
the calibration variables did not drift, shift or change values.
Dual Range or Dual Gas Calibration (Optional)
Select one of two factory calibrated flow ranges using a simple ex-
ternal customer-supplied single contact closure.
User Full Scale Flow Rate
Field-configure from 50% to 100% of the factory full scale setting
(factory full scale is normally set to 125% of the user-specified maxi-
mum flow rate). This adjustment can be made for each flow range.
Alarms
Program high and low or window alarm limits independently for
each flow range. The solid state contacts are optically isolated.
K-Factor Correction
Change the calibration correction factor to compensate for flow pro-
file disturbances or specific application conditions. The K-factor is a
multiplication factor applied to the linearized flow signal. You may
set the K-factor individually for each flow range.
Dual Output Signals
The flow meter offers two separate linear output signals propor-
tional to flow, 0-5 VDC (0-10 VDC optional) and 4-20 mA. The
4-20 mA output can be field-configured as an active loop powered
by the flow meter or an optically isolated passive loop requiring an
external power supply.