FAQ bbe AlgaeGuard

No. The AlgaeGuard does not have internal data storage for measurement results. Measurement data must therefore be transferred using one of the available interfaces:

1. Analog output: The measurement values can be transmitted via the 4–20 mA outputs to a SCADA or process control system.
2. PC software: The AlgaeGuard can be connected to a computer running the associated Windows software, where measurement data and graphs can be displayed and stored.

If neither of these options is used, the measurement result is displayed on the AlgaeGuard's grayscale touchscreen after each measurement. The result is not retained after the next measurement and will therefore no longer be available on the display.

Both instruments use the same unique bbe fluorometric measurement method. However, there are several differences in their features and intended use.

The main differences are:

• Data storage: The AlgaeGuard has no internal data storage for logging measurement data. The AlgaeLabAnalyser provides data storage through its PC-based software.
• Turbidity compensation: The AlgaeGuard does not have a turbidity compensation function, whereas the AlgaeOnlineAnalyser can compensate for the influence of turbidity on the measurement.
• Display and operation: The AlgaeGuard has a small integrated display, while the AlgaeOnlineAnalyser is operated using the bbe++ software with a larger colour touchscreen interface.

For a complete comparison, please refer to the detailed comparison table.

 

Yes. The algae concentrations calculated using the stored fingerprints can be output directly as 4–20 mA signals and therefore read by an external database or control system.

However, the fingerprint calculation algorithm cannot be provided for implementation in an external database. The calculation is performed by the instrument/software before the results are output via the 4–20 mA interfaces.

No. The raw measurement data cannot be output via the 4–20 mA interfaces. However, the raw data can be read out and stored using the associated PC software.

Yes. The algae concentrations calculated using the stored fingerprints can be output as 4–20 mA signals and therefore read directly by an external database or control system.

The calculation algorithm itself cannot be provided for implementation in an external database. The fingerprint-based calculation is performed by the instrument/software before the results are transmitted via the 4–20 mA outputs.

Yes. Alarm thresholds can be defined directly in the process control system based on the transmitted measurement values. If this approach is used, the need for the AlgaeGuard relay outputs should be evaluated accordingly.

Transmission is measured at the following wavelengths: 470 nm, 525 nm, 570 nm, 590 nm, and 610 nm.

The sample pump is a peristaltic pump and is available as an option.

If the sample pump operates continuously, the sample flow rate is 10 L/h, which is the maximum flow rate for the standard pump configuration. The AlgaeGuard can also be operated with defined measurement cycles. For example, if one measurement is performed approximately every 5 minutes, about 150 mL of sample is required per measurement. This corresponds to an average sample flow of less than 1 L/h.

No. The AlgaeGuard can also be operated discontinuously. Measurement cycles can be defined according to the application. For example, measurements can be performed at intervals of approximately 5 minutes, rather than continuously.

The recommended maintenance includes:

Weekly

• Check the inlet and outlet for blockages.
• Check the instrument for leaks by visual inspection.
• Clean the hoses.

Monthly

• Replace the pump tubing.
• Clean the measuring cuvette.