TF1100-EH transit-time handheld flowmeter manual
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3.22 HOW TO USE THE WORKING TIMER
Use the working timer to check the time that has passed with a certain kind of operation. For
example, use it as a timer to show how long a fully-charged battery will last.
Under M72, press ENT key and then select YES to reset the timer.
3.23 HOW TO USE THE MANUAL TOTALIZER
Use M28 for the manual totalizer. Press ENT key to start and stop the totalizer.
3.24 HOW TO CHECK THE ESN AND OTHERS
Every set of the TF1100-EH series flow meter utilizes a unique ESN to identify the meter.
The ESN is an 8-digit number that provides the information of version and manufacturing
date. The user can also employ the ESN for instrumentation management. The ESN is
displayed in window M61.
Other details about the instrument are the total working hours displayed in window M+1, and
the total power-on times displayed in window M+4.
3.25 HOW TO KNOW HOW LONG THE BATTERY WILL LAST AND
HOW TO CHARGE THE BUILT-IN BATTERY
Use M07 to check how long the battery will last. The instrument can operate either from the
built-in Ni-H rechargeable battery, which will last over 10 hours of continuous operation
when fully recharged, or from an external AC/power supply from the battery charger.
The battery charging circuits employ a scheme of constant-current and constant-voltage. It
has a characteristic of fast charging at the beginning and very slow charging when the battery
approaches to full recharge. Generally, when the green LED starts coming on, the battery
would be nearly 95% recharged and when the red LED is off, the battery would be 98%
recharged.
Since the charging current becomes tapered when the battery recharge is nearly completed,
i.e. the charging current becomes smaller and smaller, therefore, there should be no
over-recharging problem. That means the charging progress can last very long.
When fully recharged, the terminal voltage reaches around 4.25V. The terminal voltage is
displayed on window M07. When the battery is nearly consumed, the battery voltage drops to
below 3V. The user can obtain an approximate battery working time from the battery voltage.
A software battery working time estimator
is integrated in this instrument based on the
terminal voltage. Please note that the estimator may have relatively bigger errors in the
estimated working time, especially when the voltage is in the range of around 3.70 to -3.90
volt.
