2021.05.25
•
REV. 3
• MASS FLOW METER OPERATING MANUAL
9
Analog Signals
Primary Analog Output Signal
Most devices include a primary analog output signal, which is linear over its entire range.
For ranges that start at 0 Vdc, a zero-pressure condition is indicated at approximately 0.010
Vdc. Full scale pressure is indicated by the top of the range: 5 Vdc for 0–5 Vdc, 20 mA for
4–20 mA signals, and so on.
Option: Secondary Analog Output Signal
The default 8-pin Mini-DIN connector places the primary analog output on pin 6 for voltage
signals, and Pin 1 for 4–20 mA current signals. Ground for these signals is common on pin 8.
Using Ground to Tare
You can tare your pressure gauge remotely by momentarily grounding pin 4. When the
switch is closed, the device will tare. Operation will resume when the switch is released.
You can also tare with the front controls (
) or serial commands (
). This
should only be done in a true zero-flow condition.
Option: Second Analog Output Signal
Alicat’s default 8-pin Mini-DIN connector places the secondary analog output on pin 2 for
both voltage and current signals. Your device’s secondary analog signal may differ from its
primary output signal.
✓
Note:
See the calibration sheet that shipped with your meter to determine which output
signals were ordered.
Option: 4–20 mA Current Output Signal
If your meter has a 4–20 mA current primary or secondary output signal, your flow meter
will require 12–24 Vdc power.
▲
Caution:
Do not connect 4–20 mA devices to “loop powered” systems, as this will damage
portions of the circuitry beyond repair and void the warranty. If you must interface with
existing loop powered systems, always use a signal isolator and a separate power supply.
Pin 8
Ground
Pin 4
Pin 4
Pin 8
Connect to tare
