YOKOGAWA EXA TB TB400G, User Manual

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<5. FUNCTIONS>
5-6
IM 12E04A02-02E 9th Edition : Mar. 16, 2018-00
5.3 Manual Cleaning and Calibration Functions
Table 5.4 shows a list of manual cleaning and calibration functions. For operation and setting
procedures, see the procedures for each mode and the functions in Chapter 6.
Table 5.4 Manual Cleaning and Calibration Functions
Function Description Mode FUNCTION
1 Zero calibration (zero
water)
Zero-point calibration using zero water MAINT. 1
2 Zero calibration (lamp
OFF) *1
Zero-point calibration with the lamp turned off When the
measurement is over 200 mg/L turbidity, zero calibration
can be made at Lamp off.
MAINT. 2
3 Zero-shift calibration *3 A function to make the zero point agree with the desired
value.
MAINT. 3
4 Span calibration
(calibration plate/
standard solution)
Span calibration using the calibration plate and standard
solution.
the calibration plate and standard solution should be
selected
according to function.
MAINT. 4
5
Span calibration
(sensitivity correction) *3
A function to make the point at the upper end of the span
agree with the desired value
MAINT.
5
6
Manual start of
automatic cleaning *2
Cleaning operation can be started in the <MAINT.> mode.
MAINT.
6
7 Manual start of
automatic calibration *2
Calibration operation can be started in the <MAINT.> mode. MAINT. 7
8 Reference sensitivity
calibration
Reference span calibration carries out with standard
solution upon shipment from the factory. This sensitivity
becomes the reference of the slope display and slope
failure assessment.
Normally, this is not used except upon shipment from the
factory.
MAINT. 8
9 Lamp control reference
value
The converter lamp voltage is fixed at 3.6 V and the
reference signal voltage at the time is stored as the
reference.
The lamp voltage is controlled by this reference value.
MAINT. C
10 Setting of calibration
plate turbidity value
The calibration plate turbidity value is set (marked at the
rear of the calibration plate).
PROGRAM 1 A
11
Setting of zero
correction factor
The zero correction factor obtained in item (3) can be
displayed and changed.
PROGRAM 1
B
12
Setting of sensitivity
correction factor
The sensitivity correction factor obtained in item (5) can be
displayed and changed.
PROGRAM 1
C
13 Selection of calibration
plate/standard solution
Which span reference is used, either the calibration plate
or the standard solution, for span calibration in item (4), is
selected.
PROGRAM 1 D.
*1: The difference in the zero point between the procedures using "zero water" and the lamp being off is approximately 1 mg/L.
*2: For the automatic cleaning operation in the <MEAS.> mode, see subsection 4.2.2.
For the automatic calibration operation in the <MEAS.> mode, see subsection 4.2.3.
*3: Normal zero and span calibration is carries out using items (1) or (2) and (4) of Table 5.4 taking the standard solution as the
reference (equation 5.1). However, if the indications are to agree with the arbitrary values using a solution other than the standard
solution as the reference, calibration with items (3) and (5) of Table 5.4 is carried out. In this case, the zero correction factor and
sensitivity correction standard solution (see equation 5.2).
T1 = S (V - A) Eq. 5.1
T2 = K (T1 + B) Eq. 5.2
where,
T1: Turbidity value using standard solution as the reference
S: Span calibration coefficient (referencing to standard solution)
This is calculated when calibrating item (4) in Table 5.4, and the ration of the span calibration coefficient (S0)
calculated by reference sensitivity calibration in item (8) in Table 5.4 (normally implemented upon shipment from
the factory) to this coefficient, S0/S, is displayed as the slope in item (8).
The permissible range for item (4) in Table 5.4 is 50% <= S0/S <= 400%.
A: Zero-calibration coefficient (refered to standard solution)
This is calculated in calibration for items (1) and (2) in Table 5.4 and the turbidity-converted value of this
coefficient (S x A) is displayed as a zero-point error because of item (7) in Table 5.5.
-10 mV <= A <= 10 mV is the permissible range of items (1) and (2) in Table 5.4.