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Hanna Security Pool Plus pH/ORP, Complete Installation Kit (BL121-10)

The Security Pool Plus or BL121 is an automatic pH and chlorine measuring and dosing system which, through a combination of measuring sensors, dosing pumps and liquid chemicals, continuously measures the pH value and the content chlorine in your pool or spa and automatically maintains that level.
The Security Pool Plus is equipped with the most modern technology in the field of measurement, dosing and safety.

Easy to install and use. Delivered as a complete set, equipped with all probes, installation material, calibration fluids and manual in Dutch. The BL 121 has been a reliable partner for swimming pools for years!



Hanna Instruments Security Pools BL121-20

VAT Included |
  • Compact and digital measuring and dosing equipment for swimming pools and private spas

    Security Pool Plus combines 2 regulators and 2 dosing pumps in a single entity, controlled by a combined digital pH/redox/°C electrode, unique on the market. It is equipped with a DIN connector allowing the combined measurement of the 3 parameters and a simple, fast and secure connection. In addition, it is equipped with a differential input, protecting the signals from parasitic currents and interference from cables with insufficient shielding.

    A unique concept

    • The only controller on the market, equipped with a digital combined pH/ORP electrode with integrated temperature sensor and differential input
    • electrode immune to interference from other cables or stray currents
    • Accurate and stable measurements
    • Long life expectancy
    • Water temperature measurement
    • Quick and easy installation, calibration and maintenance

    Safe and effective

    • Combined digital pH/ORP electrode, with integrated temperature sensor and differential input
    • ¾ thread  »
    • Connecting saddle 50 mm, 63 mm, 75 mm
    • High and low alarms for each parameter: avoid overdosing of chemicals
    • Dosage”  master/slave  » intelligent: as long as the pH is not stabilized, chlorine is not injected in order to avoid any gaseous release of Cl2

    Complete set

    • Accurate and reliable measurements
    • Quick and easy to install
    • Silent peristaltic pumps with adjustable flow rates (0.5 to 3.5 l/h) for water volumes ranging from spa to swimming pool
    • Proportional dosing, slowing of the dosing when approaching the set point
    • Delay time adjustable for pH and redox (adjustable injection delay allowing stabilization of pH and redox measurements)
    • Time-out (maximum dosing period) adjustable according to pool size
    • Large backlit LCD display with simultaneous display of pH/ORP/°C
    • Password protected system configuration
    • Automatic storage of measurements every 10 seconds
    • USB port for retrieving stored data
    • automatic and safe calibration (calibration suspended if electrode deviation is too great to ensure correct calibration)
    • GLP function, storage of electrode values (offset and slope) and last calibration data
    • Display of calibration history and electrode status
    • Input for flow control (optional!)
    • Multi-color LED to indicate if the system is in measuring / dosing / alarm mode


    Automatic connection

    The values of each parameter are automatically recorded every 10 seconds: pH, ORP and °C, last calibration data, configuration parameters and event data if any. For review and storage, data can easily be transferred to a PC using a USB stick and the USB port.


    Proportional dosing

    The BL121-BL122 is equipped with proportional control metering pumps. The proportional band can be adjusted depending on the sensitivity of the process to chemical addition. This setting determines the dosing time of the pumps in % of the deviation from the set point. For example, a large amount of water will use a small proportional band. A small band (eg 0.1 pH) will cause the pumps to dose more often when the value is close to the set point. For Jacuzzis or Spas, it is more useful to set a wider proportional band (eg 1.0 pH). When the value is close to the set point, the operating time of the dosing pump is minimal to avoid large fluctuations in pH or Redox. This valuable feature allows very fine control when maintaining the desired set point.

    Adjustable flow

    The flow rate of the dosing pump is adjustable from 0.5 to 3.5 l/h. Larger ponds require a larger dosage of chemicals than smaller ones because it takes more chemicals to see a change in measurement. Adjustable flow, such as proportional band, allows greater control when maintaining a desired setpoint.


    Programmable alarm

    Low and high alarm levels can be enabled or disabled for all parameters. When an alarm is triggered, all dosing stops. The system also provides overdose protection. If the value is not corrected within a given time interval, the meter goes into an alarm state.


    Digital outputs

    The digital outputs allow you to add a number of interesting options to the system: for example, a flow switch to check the circulation of the pump or a level controller to check the liquid level in the chlorine or chlorine tank. 'acid.

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