EUTECH INSTRUMENTS ALPHA PH 800 PHORP CONTROLLERTRANSMITTER, Руководство по эксплуатации, Страница: 23 / 34

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1) Follow directions in 7.3.1 to enter Control Relay mode.
2) Press the ENTER key until the upper display shows Lo or Hi and the
lower display shows SP1 (SP2).
3) Press the
∆∆∆∆
or
∇ ∇ ∇ ∇
keys to select low (lo) or high (hi) set point for SP1
(SP2).
4) Press the ENTER key to confirm.
5) Proceed to 7.3.4 step 3 , or return Measurement mode by pressing the
∆∆∆∆
and
∇ ∇ ∇ ∇
keys simultaneously (escape).
7.3.4 Selecting a hysteresis (dead band) value
Hysteresis prevents rapid contact switching if your value is fluctuating near
the set point. It does this by overshooting the set point value to a specified
hysteresis value. You can set the hysteresis value from 0.1 to 1.0 pH, 10 to
100mV.
Example: You have set your high set point at pH 9.0 and your hysteresis
limit value at pH 0.5. If your measured value overshoots the high set point
pH 9.0, the controller’s relay activates, which in turn activates external
devices such as a pump or valve. The actions of the external device will
cause the solution’s pH to drop. When the pH drops to 8.5 pH, the relay and
hence the pump will switch off.
1) Follow directions in 7.3.1 to enter Control
Relay mode.
2) Press the ENTER key . Scroll with the
∆∆∆∆
or
∇
∇ ∇
∇
keys until the upper display shows the hysteresis
(dead band) value and the lower display shows
“HYS”.
3) Press the
∆∆∆∆
or
∇
∇ ∇
∇
keys to enter your hysteresis value for Set point 1 (Set
point 2). Your controller will activate at the value you select.
4) Press the ENTER key to confirm your selection.
0.50
pH
HYS
SETUP
HOLD