YOKOGAWA EXA TB TB400G, User Manual

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<1. OVERVIEW>
1-2
IM 12E04A02-02E 9th Edition : Mar. 16, 2018-00
1.1 System Configuration
The TB400G Surface Scattering Light Turbidity Meter comprises a detector, converter and
sampling system (which supplies process sample water, zero-calibration water (“zero water”),
and cleaning water). This instrument is classified into three types depending on the specifications
for the sampling system. However, if specified in advance, the detector and converter may be
delivered separately.
Here, four types of the instrument, including the delivery of detector and converter separately,
will be described. Details on the detector and converter are described in Section 1.2, “Operating
Principle”.
1.1.1 TB400G-
¨
-
¨
-NN, -KC (without sampling system)
The detector and converter are available separately and can be assembled into any sampling
system.
The flowrate condition for sample is 1.5 to 2 L/min. If the flowrate exceeds this range, satisfy the
flowrate condition by providing a head tank (constant-level chamber) or the like.
For measurements of low turbidity (less than 200 mg/L), prepare a sampling system which can
supply the zero water (tap water filtered with a zero-turbidity filter).
1.1.2 TB400G-
¨
-
¨
-A1 (with sampling system, without
automatic cleaning or automatic zero calibration)
This is a system which combines the detector and converter with a sampling system to manually
supply process sample, zero water, and cleaning water (see subsection 2.6.1).
The measuring water flows into a header tank (constant-level chamber), serving also as a bubble
separation tank, after passing the ball valve located after the tap water inlet port.
Debubbled sample in this tank flow into the measuring cell in the detector at a constant flowrate,
and drains through the drain outlet after overflowing at the measuring cell.
The cleaning water passes the ball valve located after the tap water inlet port and flows into
the measuring cell in the detector from the cell side. The cleaning water then starts swirling
and removes dirt on the measuring cell wall. The dirt, together with the opening the ball valve
mounted under the header tank.
During zero check, the zero water is filtered by passing through a zeroturbidity filter from the tap
water inlet. This zero water flows into the measuring cell in the detector via the head tank through
a tube separate from that for the sample and drains through the drain outlet.
1.1.3 TB400G-
¨
-
¨
-A2 (with automatic cleaning and without
automatic zero calibration)
This is a system which comprises the TB400G-

-

-A1 model with the automatic cleaning
function added (see subsection 2.6.2).
The sampling system of this system incorporates a solenoid valve at the cleaning water tube and
an electric motor-operated valve under the header tank. These provisions automatically clean the
measuring cell under the detector in a sequence preset in the converter.