Thermo Fisher Scientific Alpha DO 2000 - Manual (Page 30)

Instruction manual
Alpha DO 2000
6.4 Control Relay A / Relay B Settings (SP1/SP2)
The SP1 settings define the operating parameters for Relay A; while SP2
defines the operating parameters for Relay B. Since these two settings have
the same set-up parameters, only SP1 is described here.
SETUP SETUP
HOLD HOLD
SETUP
SETUP
HOLD
HOLD
SETUP SETUP
SETUP
HOLD HOLD
HOLD
% ENT ENT ENT
ENT
ENT
ENT
1 2 3
3
4 5
6
ENT
1. From the setup mode, select the “SP1” (Relay A) screen and then press ENT
key.
2. Setting set point value: Press ▲ or ▼ key to enter the value for set point 1
at which your controller will activate. Press ENT key to confirm your setting.
3. Selecting relay function: Press
▲ or ▼ key to select the desired relay
function (“LO”= low or “HI”= high). Press ENT key to confirm your selection.
Î NOTE: This parameter lets you choose the relay function. Select “LO” to
activate the relay when the dissolved oxygen value undershoots the low
set point; select “HI” to activate the relay when the value overshoots the
high set point. SP1 and SP2 can be selected as “Lo/Lo”, “Lo/Hi”,
“Hi/Lo”, or “Hi/Hi”.
4. Setting a hysteresis value: Press
▲ or ▼ key to select the desired
hysteresis (setting range: 1 to 10% or 0.1 to 1.0 mg/l) for set point 1. Press
ENT key to confirm your setting.
Î 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 low set point at 6.20 mg/l and your hysteresis
value at 0.5 mg/l. If your measured value undershoots 6.20 mg/l, the
controller’s relay activates. The actions of the external device will cause the
value to rise above 6.20 mg/l. The relay will deactivate, when the DO value
has increased to 6.70 mg/l (6.20 + 0.50).
5. Setting the on-delay time lag: Press
▲ or ▼ key to enter the on-delay time
for set point 1. The controller will delay activation of the relay for the number of
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