Hach Polymetron 9245 Single-Channel Sodium Analyzer

Overview

The Hach Polymetron 9245 is a single-channel online sodium analyzer for high-purity water, designed to detect trace sodium in steam, condensate and demineralised water before it causes corrosion or deposits in boilers and turbines. It measures sodium with an ion-selective electrode after the sample has been conditioned to a stable pH, and its standard range of 0.01 to 10,000 ppb is freely programmable. An optional K-kit moves the range to 1 ppb to 200 ppm for highly acidic samples taken after cation exchangers.

Seven Star LLC supplies the Hach Polymetron 9245 to power stations, independent water and power projects, refineries and industrial steam users in the Sultanate of Oman and the GCC. Our Muscat team helps you choose the panel or enclosure version, the communication option and whether automatic calibration is needed for your sodium levels.

Measurement Principle of the Hach Polymetron 9245

A sodium-selective glass electrode responds to sodium ions, but at trace levels hydrogen ions interfere, so the Hach Polymetron 9245 first raises the sample pH. Conditioning uses the siphon effect of a liquid sample column with a programmable pH set-point, and the reagent can be ammonia, monoethylamine, diethylamine or diisopropylamine (DIPA). Hach notes that no forcing gases or permeation tubing are used, and a highly absorbent cartridge reaching to the bottom of the reagent bottle keeps buffering capacity constant, giving at least 50 days of reagent autonomy.

Temperature compensation is based on the isothermal point of the electrode, and the analyzer reactivates the sodium electrode automatically by injecting a non-hazardous chemical, so manual rejuvenation by HF etching is not required. A sequential constant-head system with minimum flow detection feeds the cell, and a quick loop at the bottom of the analyzer ensures fresh sample is always available. A grab-sample vessel lets the operator introduce an off-line sample of no more than 250 mL, after which the analyzer returns automatically to online measurement.

Engineering Design of the Hach Polymetron 9245

All hydraulic and electronic components are mounted on a panel with a maximum size of 850 x 450 x 252.5 mm, and the complete unit weighs between 15 and 30 kg depending on configuration. The transmitter is rated IP65 (NEMA 4X per the engineering specification) in an aluminium housing with a stove-enamelled polyester coating; the open panel is IP50, and an optional enclosure rated IP54 keeps tubes and cables tidy, protects personnel and is designed so that DIPA vapour is collected and sent to the drain. The measuring cell is compact PMMA with minimum tubing, the inlet takes 6 mm or ¼-inch OD tubing and the outlet is a barbed stem for ½-inch hose.

The Hach Polymetron 9245 transmitter has a 128 x 128 pixel graphical display with LED backlighting, menus in English, French, German, Spanish and Italian, and three password-protected access levels. Power is 100-240 VAC, 50-60 Hz with automatic switching and a maximum consumption of 80 VA. Calibration is by manual introduction of a standard solution, or, with the AutoCal option, by fully automatic one- or two-point known addition using only ppm-level standards, which Hach recommends for applications below 10 ppb.

Key Features of the Hach Polymetron 9245

The manual and engineering specification describe these features of the Hach Polymetron 9245.

• Freely programmable range of 0.01 to 10,000 ppb sodium, or 1 ppb to 200 ppm with the K-kit option.
• Response time T90 of 180 seconds for a step from 0.1 to 10 ppb.
• Repeatability below 0.02 ppb or 1.5% of reading, whichever is greater, within a 10 °C variation.
• Automatic electrode reactivation without HF etching and reagent autonomy of at least 50 days.
• Optional AutoCal using the known-addition principle with ppm standard solutions.
• Four isolated 0/4-20 mA outputs with linear, dual or logarithmic scaling, one of which can report calibration events, warnings and system alarms.
• Two concentration relays, one warning relay and one system relay, plus start/standby and remote AutoCal logic inputs.
• Optional RS485 (Modbus) or Profibus DP communication and a 3,200-line data logger.

Industrial Applications

The manual describes the typical environment as a power station, indoor installation, demineralised water plant or instrumentation room. In Oman that means steam and water cycles at gas-fired combined-cycle plants such as those at Barka, Sohar, Sur and Salalah, where sodium on condensate, feedwater and saturated steam is an early warning of condenser leaks or carry-over. The Hach Polymetron 9245 also suits mixed-bed and polishing-plant outlets, where sodium breakthrough signals that a unit needs regeneration.

Refineries, fertiliser producers and petrochemical plants in Sohar and Duqm that run their own boilers can apply the same measurement to protect turbines and heat-recovery steam generators. Seven Star LLC supplies the Hach Polymetron 9245 with engineering support in Muscat, and can quote conditioning reagent, electrodes and standards with the analyzer.

Technical Specifications

The values below are taken from the Hach Polymetron 9245 user manual (DOC024.52.93033) and the Hach 9240/9245 engineering specification.

How to Order

To request a quotation for the Hach Polymetron 9245, tell Seven Star LLC the sample point, expected sodium range, whether the sample is cationic, and the options you need (enclosure, RS485 or Profibus, AutoCal). We will confirm the 09245 model code, advise on stock and lead time for Oman and the GCC, and the engineering specification and user manual can be downloaded from this page. Other water chemistry instruments for the same plant include the ABB AX410 conductivity transmitter, the Hach DEHA reagent 2 solution for oxygen scavenger testing and the Hach BioTector B3500ul TOC analyzer.

For dissolved oxygen on the same cycle, see the Hach Orbisphere 510 analyzer.