YOKOGAWA TB830D, User Manual, Page: 32 / 85

<3. PREPARATION for OPERATION>
3-3
IM 12E04B40-02EN 1st Edition : Mar. 08, 2023-00
3.5 Supply of zero water
If the turbidity to be measured is greater than 200 NTU, remove the element of the zero turbidity
filter.
(1) Supply the specified tap water to the mounting port of tap water.
(2) Close all valves except V2 and SV3 (for Sampling system: -A3).
(3) Loosen the knob of the air vent at the top of the zero-turbidity filter and vent the air until tap
water leaks out. After venting, tighten the knob firmly.
(4) Loosen screw A (see Figure 3.1) at the bottom of the detector and open the top of the
detector.
(5) Slowly open valve V3 to adjust the level so that it overflows from the overflow port in the
head tank, and check that the liquid level becomes the mirror surface as shown in (b) in
Table 3.2.
3.6 Leveling detector (flow rate adjustment)
The measurement surface is rippled.
B
Thread A
Detector drain outlet
Flow cell
The measurement surface is rippled.
Flow cell
Measurement surface is a mirror surface.
（ a ） Unmeasurable status
（ b ） Measurable status
Figure 3.1 Detector
Figure 3.2 The liquid level of the detector
(1) Models with a sampling system usually do not need leveling because they are factory
adjusted. ( “3.12 Supplying Sample and Adjustment flow rate” is required). When leveling
with or without a sampling system, place a level on the Flow cell with no water flowing, and
adjust at B (4 locations) shown in Figure 3.1 so that the level shows horizontal at two points
at right angles (see Figure 3.3). If there is no level gauge, it can be adjusted visually. In this
case, adjust so that water overflows almost uniformly from the Flow cell (see Figure 3.2 (b)).
(2) After leveling, measure the volume of water drained from the detector drain port (see Figure
3.1 ) using a graduated cylinder, etc., and confirm that the volume is within 1.5 L ± 0.1 L per
minute. If the flow rate is large, adjust it again in the direction of raising the Flow cell. If it is
small, adjust it again in the direction of lowering the Flow cell using B (4 positions) shown in
Figure 3.1.