Pool Controller

BL-121 is a new high performance hygiene control system for swimming pools, hot tubs and spas. It combines quick and easy monitoring for pH, ORP and temperature together with automatic chlorine dosing.

The controller is available in two versions:

• Inline system (BL-121-10) allows for direct installation of probe and chemical injection fitting into existing piping.
• Optional bypass flow cell included (BL-121-20) - ease of maintenance enhanced by allowing calibration and maintenance of the probe without the need to shut down the recirculation pump

Key features:

• Multi-coloured LED indicators for dosing
• Meter status and service
• USB Connectivity
• Real-time graph display
• Automatic logging
• Programmable alarms
• Password protection

More information:

BL-121 uses a multiparameter digital HI-1036-1802 probe that incorporates pH, ORP and temperature sensors along with a matching pin. All readings are measured within the probe and the data transferred to the controller by a digital connection.

A digital connection and matching pin provide for stable, reliable measurement. Without these two components, electrical noise from recirculation pumps and ground loops can interfere, causing erratic readings and premature probe failure.

BL-121 has two built-in peristaltic chemical feed pumps that are proportionally controlled with adjustable flow rates. One of the pumps is used to dose acid while the other is used to dose Chlorine. The effectiveness of the available Chlorine, as determined by ORP, is inversely related to pH value of the water. A pool with a fixed concentration of Chlorine will show a decrease in ORP as the pH of the water increases.

BL-121 also features a dosing consent feature that will not dose Chlorine until the pH value is first corrected. It is possible to have a low ORP value even though there is sufficient Chlorine. The dosing feature avoids this situation as well as preventing chemical wastage and having a higher Chlorine concentration level than desired.

HI-1036-1802 Multiparameter Digital pH, ORP, Temperature Probe

HI-1036-1802 is a digital probe that measures pH, ORP, and temperature. This probe also incorporates a potential matching pin. The matching pin is considered the ‘earth ground’ connection and is used to prevent ground loop effects from causing erratic readings and damage to the system.

pH glass has been chosen to produce stable quick equilibration even in low conductivity waters. Additionally, the pH sensor is designed to produce a mV value near pH 4 (not pH 7 like typical sensors) should it stop working. A broken pH electrode that produces mV value near pH 7 would produce an alarm state and disable any pump activated.

The ORP sensing surface is a large smooth surfaced platinum band that encircles the circumference of the temperature probe. It is referenced to Ag/AgCl reference electrode (3.5M KCI).

The ORP and the pH sensors and reference electrode all use a differential measurement technique designed to deliver accurate results under adverse conditions that may cause conventional pH probes to produce erroneous measurements.

The HI-1036-1802 probe with its differential amplifiers greatly reduces inaccuracies caused by ground loops which may exist between process and instrument grounds. With the differential technique, a ground loop current flows through the low impedance path of the matching pin and provide immunity to the measurement signals. In addition, the probe converts these measurements to a digital signal to eliminate noise and static due to high impedance signals carried by cable.

Both the HI-1036-1802 and the BL-121 Pool controller promote the health and safety of pool and spa water.

Liquid Crystal Display

A versatile display allows three display modes. The LCD can display all three parameters at once, a 3-second cycle of single parameters, or a real-time plot screen with options for parameter selection, zooming, and log recall.

Datalogger

For compliance monitoring, the BL-121 has a built-in datalogger. Measurement readings are logged every 10 seconds with a new log starting each new day or when the instrument is calibrated. Logged data include pH, ORP, and temperature values, last calibrated data, setup configuration, and any event data.

Analogue outputs

Three 4-20 mA analogue outputs are available for users that wish to connect to an external chart recorder or datalogger to monitor any of the three measured parameters. The outputs are scalable, offering increased flexibility and better resolution as needed.

Additional features

Additional features of the BL-121 include LED indicators for dosing, meter status and service, real-time graph display, programmable alarms, and password protection.

Liquid Crystal Display - A versatile display allows three display modes

The digital probe measures pH, ORP, and temperature. This probe also incorporates a potential matching pin.

Automatic pH control for easy HSG282 compliance

If you want to take the work out of HSG282 compliance, the BL-121-10 offers an ideal solution. As a pH and chlorine controller, you can leave the effort of balancing your hot tub or spa pool to a fully automated system. A real-time graph display provides immediate feedback on pH levels to comply with HSG282 guidelines at any time of the day.

Automatic logging also means that twice-daily pH readings don't need to be manually recorded every time. Instead, the BL-121-10 ensures your readings are stored safely, ensuring you can comply with five-year storage requirements for pH measurements.

By covering pH measuring and dosing, you have peace of mind that your customers, staff and business are protected against risks related to sickness, such as Legionnaires' disease. The BL-121-10 also fulfils HSG282 legislation relating to sanitation, keeping your commercial hot tubs and pools safe and ready for use.

Want to know more about the pH requirements under HSG282 guidelines? Read our complete guide online now to learn all about it.