Thermo Fisher Scientific Alpha pH 2000D - Manual (Page 24)

6.4 Control Relay A / Relay B (SP1/SP2) sub-function
The SP1 sub-function determines the operating parameters for Relay A; while SP2 defines the
operating parameters for Relay B. Since these groups have the same set-up parameters, they are
described together
.
SETUP
HOLD
SETUP
HOLD
SETUP
HOLD
SETUP
HOLD
SETUP
HOLD
SETUP
HOLD
hi
1 2
5 6
3
3
4
ENT ENT ENT
ENT ENT
ENT
ENT pH
pH
SETUP
HOLD
1. Select the “SP1” (Relay A) or “SP2” (Relay B) sub-function, then press the ENT key.
2. Setting set point value: press the ▲ or ▼ key to enter the value for set point 1 (set point 2) at which
your controller will activate. Press the ENT key to confirm your setting.
3. Selecting relay function: press the ▲ or ▼ key to select the desired relay function (“LO”= low or “HI”=
high). Press the ENT key to confirm your selection.
Note: This parameter lets you choose the relay function. Select “LO” to activate the relay
when the pH/ORP value undershoots the set point; select “HI” to activate the relay when
the value overshoots the set point. SP1 and SP2 can be selected as “Lo/Lo”, “Lo/Hi”,
“Hi/Lo”, or “Hi/Hi”.
4. Setting a hysteresis value: press the ▲ or ▼ key to select the desired hysteresis (setting range: 0.1 to
1.0 pH, 10 to 100mV or 1 to 10%) for set point 1 (set point 2). Press the ENT key to confirm your setting.
Note: Hysteresis prevents rapid contact switching if your value is fluctuating near the set
point. Please refer to Appendix 3 for a graphical representation of the hysteresis.
Example: You have set your high set point at pH 10.0 and your hysteresis value at pH 0.5. If your
measured value overshoots pH 10.0, the controller’s relay activates. The actions of the external device
will cause the solution’s pH to drop. The relay will deactivate, when the pH value drops below 9.5 pH.
5.
Setting the on-delay time lag: press the ▲ or ▼ key to enter the on-delay time for set point 1 (set
point 2). The controller will delay activation of the relay for the number of seconds (0 to 2000 seconds)
you select. Press the ENT key to confirm your setting
.
Note: You can set a time delay for each relay, which stops the relay from switching on the
moment the set point is exceeded. This controller lets you set a 0 to 2000 seconds time
delay before your relay activates.
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