YOKOGAWA TB830D, User Manual, Page: 40 / 85

< 4. SETTING PARAMETERS >
4-5
IM 12E04B40-02EN 1st Edition : Mar. 08, 2023-00
n How to Set Each Parameter
a . Air denoising function
You can set up enable or disable Air denoising function. To use Air denoising function, set the
function to enable.
b . Air noise detection value
Air noise detection value is used to determine whether a reading is a spike due to air bubbles or
dust. Setup is defined as a turbidity value in NTU
For the Air noise detection value check, a pre-averaging turbidity value is used. To determine the Air
noise detection value, it may be needed to know the degree of fluctuation in pre-averaging turbidity
signals. Set the value to a larger degree than the fluctuation. To know the pre-averaging fluctuation,
setup the measurement time constant (maintenance time constant in maintenance mode) to 0. The
measured turbidity value at this time is a value that is not processed by the time constant.
c . Air denoising hold time
Times hold Display power when bubbles or dust are detected.
Take into account how long air bubbles and dust stay on the scatter surface and setup them
longer. Normally, air bubbles and dust will run off the Flow cell or disappear within a short time
(in a few seconds). In practice, first set the Air denoising hold time to a shorter time, and then
increase it if the function does not work satisfactorily.
d . Denoising release time
After the Air denoising hold time has elapsed, the turbidimeter gives readings without any
processing to verify that no fluctuation occurs in turbidity readings. The time count starts at the
end of Air denoising hold time.
It is unlikely that air bubbles or dust occur consecutively. Therefore, the Denoising release time
may not need to be too short. If the Denoising release time is set too short, the response is
delayed when a sudden change in turbidity actually occurs. First set the Denoising release time
slightly longer. If something is wrong with the behavior, shorten the time.
[Instructions for Use]
Be careful when using the function since the following restrictions apply.
(1) The function works only in measurement mode. As soon as the mode is changed, the Hold
or Denoising release timer is reset and the function stops.
(2) During an Air denoising hold time period, both turbidity readings (including communication
data) and analog outputs are held. During the hold time, is displayed on the HMI.
Contact output doesn’t work by this function.
(3) The function does not run for approximately 5 seconds right after the turbidimeter is turned.
(4) If the turbidimeter is turned off and then on again while the function is running, the timer is
reset.