User Guide

26
9 RELAYS
The αlpha TDS 190 features two SPDT non-powered relays; rated for 6A at 110
VAC, 250 VAC maximum. When your process exceeds the set parameters of a
relay set point, the REL 1 or REL 2 indicator will light up.
To set parameters for relay 1 and relay 2, see Setup programs P1.0 and P2.0.
10 TRANSMITTER FUNCTION
If remote data logging is required, a 4-20 mA current loop can be connected. The
current will be proportional to the TDS value displayed on the panel and according
to the measurement range selected.
TDS Range Range No., R Cell Constant 4 mA current 20 mA current
0.00 – 10.00 ppm 1 0.1 0.00 ppm 10.00 ppm
0.0 – 100.0 ppm 2 0.1 0.0 ppm 100.0 ppm
0.0 – 100.0 ppm 3 1 0.0 ppm 200.0 ppm
0 – 1000 ppm 4 1 0 ppm 1000 ppm
0.00 – 5.00 ppt 5 1 0.00 ppt 5.0 ppt
0.00 – 10.00 ppt 6 1 0.00 ppt 10.0 ppt
0.0 – 100.0 ppt 7 1 0.0 ppt 100.0 ppt
0.0 – 100.0 ppt 8 10 0.0 ppt 100.0 ppt
The 4-20 mA current loop can drive a load resistance of no more than 200 Ω.