Page 7 Instruction manual Parker X-Flow FM-1407 Rev - 11/2021
1.5.4 Calibration
X-Flow™ instruments are Nitrogen calibrated. X-Flow™ instruments are delivered with a Calibration
Certificate. Precision Fluidics certifies that all instruments meet the rated accuracy.
The calibration is converted to the customer’s gas and conditions using a detailed conversion model.
This conversion adds a level of calibration uncertainty described below.
Basic rule for calculating the conversion uncertainty is typical:
Uncertainty < 2% x CF for CF > 1
Uncertainty < 2% / CF for CF < 1
With CF defined as the approximate conversion factor, which can be calculated with:
2
1
2
1
ρ
ρ
⋅
⋅
=
p
p
C
C
CF
in which:
n
p
C
specific heat
n
ρ
density at normal conditions
(1)
calibration fluid (N
2
)
(2)
customer fluid
Contact the factory for more information.
1.5.5 Features
Each instrument consists of an Analog interface, a digital RS-232 interface and a digital
Modbus®/RS485 interface. The analog and the digital interface can be used together at the same time.
According to the pin-designation both RS232 and Modbus®/RS485 are assigned to the same pins.
When connecting these pins to either of the two, the instrument will automatically detect which protocol
to use.
Digital operation adds many extra features (compared to analog operation) to the instruments.
Such as:
•
Setpoint slope (ramp function on setpoint for smooth control)
•
Direct reading at readout/control module or host computer
•
Several control/setpoint modes (e.g. purge/close valve)
•
Identification (serial number, model number, device type, user tag)
•
Adjustable controller settings for custom controller response
Summary of Contents for X-Flow FM-1407
Page 1: ...11 FM 1407...
