Introduction:
EC/TDS-6800 online Conductivity / TDS / Resistivity controller can continuously measure and control conductivity/ TDS / Resistivity value of water.
It is widely used for the science laboratory equipment, chemical, pharmaceutical, environmental protection, metallurgy, paper making, food, beverage, water supply industry, etc.
In accordance with the environment and characteristics of water industry, as well as the international power supply standard, considering the electricity design in special environment, the Conductivity / TDS / Resistivity controller could be supplied with power 220V AC( Standard), 110V AC and safe low voltage 24V AC, 24V DC(Optional)
Main Features:
English language display
MeasureConductivity/TDS/Resistivity and Temperature, high/low limit relay control output , 4-20mAcurrent output, digital Modbus RS485 communication output (Optional)
High/lowlimit alarm light, double relay, alarm delay could be set
Instrument mode isolated transmitting port, max circle resistance up to 750Ω
PIDcontrol to actuate and control powered variable value through 4-20 mA output (optional)
Backlight of LCD could select power saving mode, timing automatic off, brightness adjust,
Conductivity constant input directly function or to calibrate probe constant as per known calibration solution’s conductivity value
High performance CPU, good electromagnetic compatibility
AC input be fusedfunction
ESDover voltage protection is available
Main Technical Index

Outline dimensions and fixed Installation
Insert the controller from the front panel, install the fix clamp
(up and down), tighten with the screws.
Chart 1 Fixed support installation
1、Probe constant selection:

Chart 2
2、Probe installation type

4-20mA current output formula
1.PH Current output formula:
Factory setting define output current value is :0 pH is corresponding value of 4 mA; 14 pH is corresponding value of 20 mA.
I = ( D - 4 mA corresponding value)× ( 16 / (20 mA corresponding value- 4 mA corresponding value) ) + 4.00
I = ( D - 0 )× ( 16 / 14 ) + 4.00
Note: I is output current value 4 mA≤I≤20 mA
D is pH value displayed by the instrument 0.00pH≤D≤14.00pH
2. Formula of ORP current output:
Factory setting define the output current is :-2000mV is corresponding
value of 4 mA; +2000mV is corresponding value of 20 mA.
I = ( D - 4 mA corresponding value )× ( 16 / (20 mA corresponding value - 4 mA corresponding value) ) + 4.00
I = ( D – (-2000) )× ( 16 / (+2000 – (-2000)) ) + 4.00
I = ( D + 2000 )× ( 16 / 4000) ) + 4.00
Note:I is output current value 4 mA≤I≤20 mA
D is ORP value displayed by the instrument -2000mV≤D≤+2000mV