Zeroing Function; Through Lcd Display Switches - Oval ALTI mass CA00A Instructions Manual

L -- 740 -- 28 -- E

9.8 Zeroing Function

This feature detects errors in zeroing and reduces offset flowrate drift to minimum. At the stage of
installation and in cases where flow conditions significantly change, zeroing is an essential part of the
routines required for maintaining accurate and consistent measurement.
During the zeroing, fill the sensor unit completely with the fluid the temperature of which is within ±10℃
from the temperature at which it operates.
CAUTION: 1. Before using this function, close both the display lid and the terminal lid of
the transmitter and make sure that the transmitter is in the condition as the
actual operating condition.
2. Fluid (liquid or gas) must completely fill the sensor unit and be absolutely at
zero flow.
3. Accurate zeroing cannot be achieved unless fluid flow is completely halted.
4. Ensure that the shutoff valve has no leaks.
Zero adjustment comes in three options: with LCD switches, with status input, and through
communication. Each has identical functions. Choose one that best suits your task.

9.8.1 Through LCD display switches

(1) Bring up the item of function you want to use.
Click "SEL1".
(2) Confirm zero flow
Click "SEL3".
Click "ENT".
Click "ENT".
(3) Confirm precautionary notes during zeroing.
Click "SEL3".
Click "ENT".
Click "ENT".
(4) Confirm before performing the zeroing
(5) Zeroing in progress
(6) Auto zero results
Zeroing successful
★
3 sec elapsed
★

Firstly, proceed key operation to show Calibration (Auto Zero) screen.
(For the procedure to view individual items, see 9.2.2 thru 9.2.7 Transition chart.)
When the cursor is placed over zeroing (Auto Zero), click "SEL1" to bring up the next
confirmation screen.
Shut off valves before after the meter and verify that fluid flow is halted.
Upon confirmation of steady state, click "SEL3" to proceed to the next screen.
If fluid flow is not completely halted, click "ENT" followed by clicking "SEL3".
Do not attempt zeroing. (Ensure zero flow once again before you perform zeroing.)
Click "SEL3".
Performing zeroing overwrites previous zero setting.
Reconfirm. If no problem is found, click "SEL3" to proceed to the next screen.
If you want to reconfirm the state, click "ENT" followed by clicking "SEL3". Do not
attempt to run zeroing. (Upon reconfirmation of the state, perform zeroing.)
Click "SEL3".
The current zero offset is shown.
If you want to perform zeroing, click "SEL3" to proceed to the next screen.
If you want to reconfirm the state, click "ENT" followed by clicking "SEL3". Do not run
zeroing. (Upon reconfirmation of the state, you may perform zeroing.)
Click "SEL3".
Zeroing is now in progress. (During the zero adjustment, GRN LED blinks on and off.)
As a warning, RED backlight lights for 1 sec at start and end of zeroing.
(Zeroing lasts for 30 sec. approx.)
Upon completion of auto zero, results are indicated; 3 sec later, the window returns to menu select screen.
If zeroing has failed, you cannot expect accurate measurement in this state.
Reconfirm the state and perform the zeroing once again.
In case of auto zero failure, an error message "Auto Zero Failure" appears.
(For details, see 10.1 Error Messages.)
Zeroing failed
★
3 sec elapsed
★
NOTE: This function is disabled in Write Protect
mode (refer to section 9.2).