TF1100-EH transit-time handheld flowmeter manual
1
PART-1 INTRODUCTION
1.1 GENERAL
Series TF1100-EH ultrasonic flow meters feature advanced Transit-Time measuring
technology, providing accurate and reliable flow rate and total flow display, The TF1100-EH
utilizes a non-invasive transducer which is hand-held or strapped to the outside of a pipe,
which will provide benefits of non-fouling operation and ease of installation.
TF1100-EH transit time flow meters utilize two transducers that function as both ultrasonic
transmitters and receivers.
The transducers are clamped on the outside of a closed pipe at a specific distance from each
other. The transducers can be mounted in V-mode where the sound transverses the pipe two
times, W-mode where the sound transverses the pipe four times, or in Z mode where the
transducers are mounted on opposite sides of the pipe and the sound crosses the pipe once. This
selection is based on pipe and liquid characteristics. The flow meter operates by alternately
transmitting and receiving a frequency modulated burst of sound energy between the two
transducers and measuring the time interval that it takes for sound to travel between the two
transducers. The difference in the time interval measured is directly related to the velocity of the
liquid in the pipe.
1.2 APPLICATION VERSATILITY
The
TF1100-EH flow meter can be successfully applied on a wide range of metering
applications. The simple to program transmitter allows the standard product to be used on pipe
sizes ranging from 20mm -6000mm internal diameters. A variety of liquid applications can be
accommodated: ultra-pure liquids, potable water, chemicals, raw sewage, reclaimed water,
cooling water, river water, plant effluent, etc. Because the transducers are non-contacting and
have no moving parts, the flow meter is not affected by system pressure, fouling or wear. Standard
transducers are rated to 85
°
C.
1.3 USER SAFETY
The TF1100-EH employs modular construction and provides electrical safety for the operator.
The display face contains voltages no greater than 5Vdc. All user connections are made
through sealed bulk-head plugs located on the side of the TF1100-EH enclosure.
1.4 DATA INTEGRITY
Non-volatile flash memory retains all user-entered configuration values in memory for several
years, even if power is lost or the unit is turned off. Data Logger values are stored in flash memory in
the logger. Password protection is provided as part of the Security menu and prevents
inadvertent configuration changes or totalizer resets. A time-keeper is integrated in the flow
meter for the index of date totalizing and works as the time base of flow accumulation. It
keeps operating as long as the battery’s terminal voltage is over 1.5V. In case of battery
failure, the time-keeper will not keep running and it will lose proper time values. The user
must re-enter proper time values in case the battery becomes totally exhausted. An improper
time value affects no other functions but the date totalizer.
