Yamatake 900 Series, Руководство пользователя

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Yamatake Corporation Installation
ST3000 Smart Transmitter Series 900 Electronic Differential Pressure/Pressure Transmitter 4-7
This condition can be expressed with the following formula;
Therefore,
Remarks
1. An application where the pressure in the tank P
0
becomes a vacuum requires spe-
cial caution.
2. If the above condition is not met, the pulling force applied to the diaphragm surface
will exceed the specified range.
Foaming occurs because the pressure of sealed liquid exceeds the saturated vapour
pressure and can cause zero point shifting. Negative pressure applied to the dia-
phragm can cause buckling and destroy the diaphragm.
3. When the liquid contacting temperature exceeds the levels shown in the table, the
low limit of the allowable pressure also changes. Check the specifications.
4. *1. STR9 †† -1, STE9 †† -1
*2. STR9 †† -3, STE9 †† -3
*3. STR9 †† -4, STE9 †† -4
*4. STR9 †† -7, STE9 †† -7
*5. STR9 †† -2 & -5STE9 †† -2 & -5
Table 4-2
Specific gravity
of sealed liquid
ρ
'
Low limit of
allowable
pressure
P (kPa abs.)
Liquid
contacting
temperature
range
( ° C)
General application (*1) 0.935 2 -40 - 40
High temperature application (-*2) 1.07 2 -5 - 90
High temperature & vacuum appli-
cation (*3) 1.07 0.1333 -5 - 50
High temperature & high vacuum
application (*4) 1.09 0.1333 -10 - 250
Oxygen application, chlorine
application (*5) 1.87 53 -10 - 40
P
0
ρ′
h
( )
102
⁄ ( )
+ P 1 kPa 102 mmH
2
O =
( ) ≥
h P
0
P –
( )
102
ρ′ ( ) ⁄ × ≤