Toshiba GF642 Manual

Field Intelligent Device
ELECTROMAGNETIC FLOWMETER
Introduction
The electromagnetic flowmeter uses Faraday's Law of
electromagnetic induction to measure the process flow.
The device consists of two units: a detector, through
which the fluid to be measured flows and in which
low-level signals proportional to flow rates are
obtained; and a converter, which supplies excitation
current to the detector, and amplifies the signals from
the detector and then processes and converts the signals
into the 4–20 mAdc current signal or communication
signal. Combined with a multi-functional converter
LF622 (separate type) equipped with its patented
Noise-Sentry original noise- suppression circuit and
advanced algorithms. The GF642 has a very high
tolerance to noise, giving the unit a very stable output
even for slurry fluid measurement. IR (Infrared)
switches enable parameter setting of the converter
without removing the cover. Flow direction can be set in
either way.
The AF900 hand-held terminal (HART
can be used to communicate with the flowmeter from a
remote place. PROFIBUS-PA
is available as an option.
*1: HART protocol (Highway Addressable Remote Transducer)
is a communication protocol for industrial sensors
recommended by the
Foundation).
*2: PROFIBUS is the communications protocol for factory and
process automation that the PROFIBUS Organization
recommends. Instead of analog control with a conventional
analog signal (4-20 mA), it is fieldbus which digitizes all
signals. Flowmeters support PROFIBUS-PA.
*3:Modbus is the communication protocol that Modicon Inc.
developed. Physical layer is RS485.
C o n v e r t e r ( L F 6 2 2 )
P o w e r c a b l e
S i g n a l a n d E x c i t a t i o n c a b l e
Figure1. Configuration
Certification
number
Z01207
*1
communicator)
*2 *3
or Modbus interface
HCF (HART Communication
D e t e c t o r ( G F 6 4 2 )
20" to 80"(500mm to 2000mm)
Figure2. GF642 Flowmeter
General Specifications
Measurement range: (measuring range by flow
Meter size
Measuring range
Accuracy: (Accuracy when combined with the
converter LF622)
Flow rate
1.0 ～ 3.28 ft.s
(0.3 ～ 1.0m/s)
0 ～ 100%FS ±0.8% FS
Note: The accuracy above is measured under
standard operating conditions using the
weighing method at Toshiba admitted
flow calibration facility.
Fluid conductivity:
5µS/cm minimum
Fluid temperature:
14 to 140 °F (-10 to +60℃)
: 20" to 36" (500mm to 900mm)
14 to 104 °F (-10 to +40℃)
: More than 40" (more than 1000mm)
GF642/LF622
(Separate type)
rate conversion)
From 20" to 80"
(500mm to 2000mm )
0-1.0ft/s to 0-32.8ft/s
(0-0.3m/s to 0-10m/s)
Flow speed of full scale
3.28ft/m ～ 32.8ft/s
(1.0 ～ 10m/s)
±0.5 %FS
EJL-146C