Water Hardness Analyzer and Control System

Water hardness is caused by the presence of Calcium and Magnesium Carbonates. The ratio of calcium to magnesium is generally fixed geographically, typically in the ratio 3:1 (Ca:Mg), therefore Total Hardness can be inferred, by knowing the amount of calcium present.
RealTech Controls offers two types of Water Hardness Analyzers, namely:

  • The T80 Transmitter using the S80 Calcium Ion Sensor. This is an ion selective electrode, measuring the amount of Calcium in the water.

  • The second is the CA-6 colorimetric Water Hardness Analyzer. This uses buffers and chemical solutions to determine the amount of Calcium Carbonate in the water.

The unit of Water Hardness measurements is usually ppm (milligrams/liter) Calcium Carbonate (CaC03) and a normal working range is 0.1 – 10 ppm. The most common method of softening is by ion exchange using resin beds (traditionally referred to as Sodium Zeolite). The Sodium ion attached to the resin is exchanged for the Calcium and Magnesium ions. Another method is “precipitation” (lime), but this is gradually being replaced by ion exchange. The same ECD equipment will work for both methods; but please check if the application is a hot lime process.

Magnesium is more soluble than Calcium and so it is more readily replaced by Sodium. This means the first indication that the softener train is failing is the increase of Calcium in the effluent. The ECD measurement/ control package is used to detect this “breakthrough” of Calcium, indicating the need for the bed to be regenerated and a new bed to be switched in.

Sodium Zeolite does not reduce the alkalinity of the softened water; in some installations a Hydrogen Zeolite softener is run in parallel to the Sodium and the resulting effluents blended to give the desired pH (this provides an opportunity to quote for pH). The softener regeneration requires acids or bases (depending on the exchange method) requiring Conductivity measurement, as % acid or % base.

Products

Water Hardness Analyzer

Model: T80 + S80

(Calcium Ion Selective Electrode)

T80 Water Hardnesss Analyzer
  • Measurement Range: 20ppb to 40,000ppm (3-11 pH), 5 x 10-7 molar to 1.0 molar
  • Temperature Range: 0°C to 40°C (32°F to 104°F)
  • Pressure Range: 0 to 50 psig (0 to 3.5 bar)
  • Response Time: T90 in 10 seconds
  • Electrode Life: 6 to 12 months
  • Interfering ions: Lead (ll), Mercury (ll), Iron (ll), Ammonium
  • Wetted Materials: Radel, epoxy, PVC, PTFE, 316 SS, Viton O-Ring
  • Process Connections: S80 Insertion: 3⁄4” MNPT compression fitting
  • S80 Valve Retractable: 1” MNPT Ball Valve
  • Outputs: Single or dual channel 4-20mA outputs, with optional Relays, Modbus, or HART
  • Industrial wastewater
  • Drinking water
  • Industrial effluents
  • Effluent and influent monitoring
  • Boiler feed water
  • Condensate and cooling water
  • Surface water
  • Process water

Water Hardness Analyzer

Model: CA-6

(Calcium Carbonate Colorimetric)

CA-6 Water Hardnesss Analyzer
Simple

  • Easy installation
  • User friendly
  • Menu structure
  • Touchscreen interface
  • Easy process configuration

Reliable

  • Epoxy powder coated
  • Rugged cold rolled steel cabinet
  • Two separate compartments (electronics hydraulics)
  • Loss of sample & low reagent alarms

Cost effective

  • Low maintenance
  • Adjustable cycle time to minimize reagent usage
  • Industrial wastewater
  • Drinking water
  • Industrial effluents
  • Effluent and influent monitoring
  • Boiler feed water
  • Condensate and cooling water
  • Surface water
  • Process water