FDT-25 Handheld Ultrasonic Flowmeter
17
§3.8 How to restore the flow meter with default setups
Use M37, when the ‘selection’ message is displayed. Press the dot key first and the message ‘Master
Erase’ will display, then press the backspace key
The master erase step will erase all the parameters entered by the user and setup the instrument with
default values.
§3.9 How to use the damper
The damper acts as a filter for a stable reading. If ‘0’ is entered in window M40, that means there
is no damping. A bigger number brings a more stable effect. But bigger damper numbers will prevent
the instrument from acting quickly.
Numbers 0 to 10 are commonly used for the damper value.
§3.10 How to use the zero-cutoff function
The number displayed in window M41 is called the low-cutoff value. The flow meter will replace
these flow rate values that are absolutely less than the low-cutoff value with ‘0’. This means the flow
meter will avoid any invalid accumulation when the actual flow is below the zero-cutoff value.
The low-cutoff value does not affect the flow measurement when the actual flow is absolutely greater
than the low-cutoff value.
§3.11 How to setup a zero point
There exists a ‘Zero Point’ with certain installation which means the flow meter will display a non-
zero value when the flow is absolutely stopped. In this case, setting a zero point with the function
in window M42 will bring a more accurate measurement result.
Make sure that the flow is absolutely stopped, then run the function in window M42 by pressing
the ENT key.
§3.12 How to get a scale factor for calibration
A scale factor is the ratio between the ‘actual flow rate’ and the indicated value by the flow meter.
The scale factor can be determined by calibration with flow calibration equipment.
§3.13 How to use the operation locker
The system locker provides a means of preventing inadvertent configuration changes or totalizer
resets.
When the system is locked, menu window browsing can be done without affecting any change, but
any modifications are prohibited.
The system can be locked without a password or with a one 1 to 4 digit password. With a no-password
locking, directly press the ENT key when the password input prompt displays.
If the password is forgotten, please contact the factory.
