User Guide

Operating Instructions αlpha-RES1000

1 Introduction

1.1 Description of Unit

Thank you for purchasing Eutech’s ¼ DIN alpha-1000 series Resistivity process controllers. This

unit is used for measuring the Resistivity of a solution in mega-ohms. You can use this unit to

measure Resistivity with limit control. This controller has many user-friendly and safety features

which include:

• Menu-driven program that simplifies set-up

• Two ranges of Resistivity measurements-software selectable (Section 7.5.3).

• Built-in memory backup to ensure that calibration data and other information are not erased

if power supply fails

• Automatic temperature compensation (ATC) with Pt100 or Pt 1000

• Manual temperature compensation with independent setting for calibration and process

temperature

• Temperature coefficient variable between 0.00 to 10.00 % per

C. Separate pure water

compensation curve stored in memory. Reference temperature at 25

• 0 to 1999 second time delay adjustment on all relays – minimise false alarms

• Separately adjustable high and low set point hysteresis (dead bands) prevent chattering of

relays around the set points. Selectable Filter function stabilises rapid measurement changes.

• Three control modes: limit, proportional pulse length or proportional pulse frequency.

• Large dual display LCD for easy reading with clear multiple annunciators, alarm status and

operational message annunciators

• Two switching contacts as set-point triggering relays and an alarm output relay

• Separate alarm relay alerts you when set points have exceeded the limits and if the

Pt100/Pt1000 wires are broken or disconnected during the ATC function

• Hold function freezes output current (0/4...20mA) and releases control relays

• LED indicators signal control activities to monitor controller status from a distance

• Protection against electromagnetic interference - galvanically isolated 0/4..20mA output

provides safety for data logging and control purposes

1.2 Applications

Use this controller in panel mounted enclosures for applications in Pure water and R.O. Systems.