Specifications – Hach-Lange SI794 P User Manual User Manual
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Specifications
Output 2
0/4 ... 20 mA, max. 10 V, floating
(galv. connected to output 1)
Process variable
Temperature
Overrange*
22 mA in the case of temp error messages
Output averaging filter *
Low-pass, filter time interval 0 ... 120 s
Measurement error
1
< 0.3% current value + 0.05 mA
Start/end of scale *
20 ... 200 °C / -4 ... 392 °F
Span allowed
20 ... 220 K (36 ... 396 °F)
Power output
For operating an ISFET adapter
+3 V (V
0
= 2.9 ... 3.1 V / R
i
= 360 Ω
–3 V (V
0
= -4.8 ... –3,7 V / R
i
= 360 Ω
Alarm contact
Relay contact, floating
Contact ratings
AC< 250 V / < 3 A / < 750 VA
DC< 30 V / < 3 A / < 90 W
Contact response
N/C (fail-safe type)
Alarm delay
0000 ... 0600 sec
Limit values
Output via relay contacts R1, R2
Contacts R1, R2 floating but inter-connected
Contact ratings
AC< 250 V / < 3 A / < 750 VA
DC< 30 V / < 3 A / < 90 W
Contact response *
N/C or N/O
Delay *
0000 ... 9999 s
Setpoints *
As desired within range
Hysteresis *
00.00 ... 05.00 pH / 0000 ... 0500 mV
PID process controller
Output via relay contacts R1, R2 (see limit values)
(Relay R1: base valve, relay R2: acid valve)
Setpoint specification *
pH -02.00 ... 16.00 / -1500 ... +1500 mV
Neutral zone *
pH 00.00 ... 05.00 pH / 0000 ... 0500 mV
P-action component *
Controller gain KP: 0010 ... 9999 %
I-action component *
Reset time Tr:
0000 ... 9999 s
(0000 s = no integral action)
D-action component *
Rate time Td:
0000 ... 9999 s
(0000 s = no derivative action)
Controller type *
Pulse length or pulse frequency controller
Pulse period *
0001 ... 0600 s, min. ON time 0.5
(pulse length controller)