YOKOGAWA EXA TB TB400G, User Manual

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<6. PROCEDURES FOR CONVERTER OPERATION>
6-22
IM 12E04A02-02E 9th Edition : Mar. 16, 2018-00
(11) By pressing the [ENT] key, the upper and lower => H020.0 mg/L
limits are entered. The entire display flashes once.
(12) When the [ENT] key is pressed, the procedure => L05.00 mg/L
returns to 1.
In operation of step 6 or 11, if the upper and lower limits are beyond the permissible range (0 to
2000 mg/L), "not" is displayed. In this case, reset the message by pressing the [>] key and repeat
the operations from step 2.
Also in step 11, if the span between the upper and lower limits does not meet the following
conditions when checked, "not" is displayed. Reset the message by pressing the [>] key in a
similar manner and repeat the operations from step 2.
Range span (Upper limit - lower limit) ≥ 20% of the upper limit ≥ 2.00 mg/L
If the upper and lower limits are only to be confirmed, pressing the [ENT] key alternately displays
L and H.
If the auto-range switching function is to be used, set the ranges as shown below.
• Set 0.00 mg/L for all lower limits (L).
• Set the upper limits (H) in the following manner.
Range 1 ≤ Rang 2 ≤ Range 3
• If two-range operation is required, set Range 2 = Range 3.
• If one-range operation is required, set Range 1 = Range 2 = Range 3.
(2) Setting Averaging Coefficient (time constant) (FUNCTION "4")
The converter display and analog output are computed for average by the program. In this
setting, the extent of averaging (signal time constant) can be changed. Table 6.9 shows an
approximate correspondence between the averaging coefficient and a 90% response time.
The 90% response time is about the averaging coefficient x 0.75 seconds. This coefficient is
set at 30 (about 22 seconds for a 90% response time) upon shipment from the factory. If the
fluctuation of measured readings is large, e.g., due to suspended matter in the measurement
object, change the averaging coefficient as necessary.
Table 6.9 Averaging Coefficient and 90% Response Time
Averaging coefficient Standard for 90% response time
10 Approx. 8 sec.
20 Approx. 22 sec.
30 Approx. 15 sec.
40 Approx. 30 sec.
50 Approx. 38 sec.
100 Approx. 75 sec.
The following is the procedure for the setting operation.
(Example of display)
(1) Select FUNCTION "4" in the <PROGRAM1> => 00030
mode.
(2) Press the [>] key. => 0 0030
The most significant digit flashes.
(3) Select a digit using the [>] key and set it to the => 000 40
desired value using the [^] or [v] key. The flashing digit moves to the right
and when the least significant digit is
reached, it returns to the most
significant digit.