LRF-3000H Handheld Ultrasonic Flowmeter
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8.
Product Overview
8.1
Introduction
The Model LRF-3000H Handheld Ultrasonic Flowmeter is a state-of-the-art universal transit-time
flowmeter designed using SLSI technology and low-voltage broadband pulse transmission. While
principally designed for clean liquid applications, the instrument is tolerant of liquids with the small
amounts of air bubbles or suspended solids found in most industrial environments.
8.2
Features of Flowmeter
With distinctive features such as high precision, high reliability, high capability and low cost, the
flowmeter features other advantages:
1. With SLSI COMA chip, low power consumption, high reliability, anti-jamming and outstanding benfits.
2. Clear, user-friendly menu selections make flowmeter simple and convenient to use.
U.S., British and Metric measurement units are available. Meanwhile, almost all-universal measurement
units worldwide may be selected to meet customer’s requirements.
3. Daily, monthly and yearly totalized flow: Totalized flow for the last 64 days and months as well as for
the last 5 years are may be viewed. Power on/off function: allows the viewing of time and flow rate as
power is switched on and off 64 times. Also, the flowmeter has manual or automatic amendment during
offline sessions.
4. With the SD Card, 512 files can be stored; the time interval can be within 5 seconds.
5. Parallel operation of positive, negative and net flow totalizes with scale factor and 7 digit display.
The flow meter ensures the higher resolution and wider measuring range by the 0.04nS high resolution,
high linearity and high stability time measuring circuit and 32 bits digits processing program.
8.3
Theory of Operation
When the ultrasonic signal is transmitted through the flowing liquid, there will be a difference between
the upstream and downstream transit time (travel time or time of flight), which is proportional to flow
velocity, according to the formula below.
down
up
T
T
T
MD
V
•
∆
×
=
θ
2
sin
Remarks:
V
Medium Velocity
M
Ultrasonic frequency of reflection
D
Pipe Diameter
θ
The angle between the ultrasonic signal
and the flow
T
up
Transit time in the forward direction
T
down
Transit time in the reverse direction
ΔT=T
up
–T
down
Downstream Transducer
Upstream Transducer
Flow
D
T
down
T
up
