System Overview

PSA are proud to present the 10.256 Online Excalibur, for the online analysis of hydride forming elements including: arsenic, selenium, antimony, tellurium and bismuth. The EPA classes the hydride forming elements as toxic and states they must be controlled in effluent streams – where high concentrations may have an adverse effect on health and wildlife in the surrounding area. The EPA have lowered the accepted concentrations of the toxic elements to low ppb (µg/L) levels. Other regulation bodies worldwide are also tightening their restrictions on effluent streams, creating a demand for highly sensitive instruments.

The 10.256 system is based on hydride generation – atomic fluorescence spectroscopy providing high sensitivities into the ppt levels (ng/L) and great linear ranges. Boosted discharge hollow cathode lamps are used to excite the element of interest at a characteristic wavelength offering great selectivity. The lamps can be swapped allowing for one instrument to analyse multiple different elements.

Representative grab samples are taken from a stream using the PSA sampling system. The sample is then pulled into the analyser via a syringe for analysis. The analyser can remove interfering sample matrices and may be used for a wide variety of aqueous samples; for example, wastewater, drinking water and sea water. PSA have worked with several sample matrices in the past; application notes can be requested from the link below.

More information about the sampling systems can be found here


The chemistry section of the instrument follows the design of the proven PSA 10.226 Online Mercury Analyser. Syringe technology is used to pull samples, reagents and standards for digestion and analysis. The use of a syringe over peristaltic pumps allows for reduced reagent consumption, reduced waste and low running costs.

The system features on board digestion, with a UV digestion module for photolysis of any organometallic species and an optional heater module for a more rapid efficient digestion process.

PSA have worked with all hydride forming elements closely and studied several sample matrices. Application notes on differing chemistries, digestion techniques, environmental sampling and much more have been produced. Application notes can be requested from the link below.

Application Notes

The Gas/Liquid Separator designed by PS Analytical has been optimised to reduce moisture presence and sports an antifoaming design. The system also includes a cooling system to keep the GLS a constant temperature. This allows for optimal performance including great precision and accuracy of results and requires no maintenance.

Some specifications for the 10.256 Online Excalibur are found below along with a standard calibration for arsenic (0 – 50 ppb). The correlation coefficient achieved was 0.99999, and the calibration finished within 40 minutes (Under 10 minutes per standard analysis).

Customisable Software

The system is supplied with the P S Analytical C210S007 Online software package as standard. This gives the administrator complete flexibility over system control. Parameters such as stream selection, analysis frequency, maintenance scheduling can all be controlled by the end user. The admin can limit the control of the instrument to other operators by introducing a multi-tier login system.

The software records all results and can generate reports which can be printed for easy record keeping or exported to excel for data analysis. The report includes visual data such as trend graphs to provide a quick summary of the collected data.

Remote Access

The online system has been designed with remote access in mind. The software can be configured to routinely send data, alarms and reminders via email. The system also can be remotely controlled over Ethernet /Internet enabling remote diagnostics to be carried out.

Alarm Systems and Outputs

The configured alarms allow for minimal operator intervention and saves time for all users. As standard the PSA 10.226 analyser comes with 4-20mA outputs and 4 relays (contact closures) for alarms.

Additional 4-20mA and contact closures and digital outputs can be easily added, as well as MODBUS RTU, RS 232, OPC Server and OPC Client.
Optional reagent level sensor probes are available from PS Analytical. The sensors can detect when the volume of reagents is low and automatically notify the user to replace or replenish the reagents.

More information about the Reagent Level Sensor Probes can be found here

Information Request

For more detailed information on the system, output options and software possibilities, please fill out an information request form here

The PSA 10.256 Analyser has superseded the 10.255 Online As / Se / Sb Analyser. Click here for information on the 10.255 Analyser.