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Doc. no. : HTMF_Kor_2016, Rev. 0
Issued date : 2016. 11
HITROL Co., Ltd
1.3
Terms and definitions
1.3.1
HTMF-MF
This generally refers to a multipoint thermal dispersion
–
type flow meter.
1.3.2
Flow Meter (F/M)
The F/M comprises a flow element and a flow transmitter.
1.3.3
Flow Element (F/E)
The F/E, which measures actual flow, comprises a sensor element that has sensors, and a
duct flange that can be attached to a duct.
1.3.4
Flow Transmitter (F/T)
The F/T calculates flow with embedded software from the values collected by the
F/E, and transmits the calculated values promptly.
1.3.5
Sensors
Sensors are core parts of the F/E, and are categorized into active sensors (Sa) and
reference sensors (Sr).
1.3.6
Sa and Sr
Sa and Sr refer to active sensor and reference sensor, respectively. They are sensors for
measuring temperature of heaters and air, respectively.
1.3.7
Ra
and Rr
They refer to resistance values of Sa and Sr, respectively.
1.3.8
ΔR
This refers to the difference between Ra and Rr (Ra
−
Rr = ΔR)
1.3.9
PWM
PWM stands for pulse width modulation.
1.3.10
Loader (HHT-2000)
This is an external terminal device that displays the values of the F/T and enables
configuration thereof.
1.3.11
Simulator
This refers to the decade resistance box that is used for replacement of input
signals of the F/E, and for calibration or functional checking of the F/T.
1.4
Composition
This instrument, F/M, comprises an F/E and an F/T.
The F/E, which measures actual flow, comprises a sensor element that has sensors, and a duct
flange that can be attached to a duct.
The flow data collected by the F/E is calculated and
converted by the software embedded in the F/T.
The F/T has an average life of no shorter than
