Calibrate & create FDA-compliant audit trail for pH, oxygen, conductivity & chlorine sensors.

Endress+Hauser has introduced Memobase Plus calibration software for pH, oxygen, conductivity and chlorine sensors. The software turns a PC into a calibration laboratory, providing complete traceability of test solutions, sensors, calibrations and measurements.

Calibration reports are generated automatically as a PDF document, or as a CSV file that can be exported to Excel or similar software for further processing.  An audit trail, user administration settings and passwords guarantee security. Memobase Plus is FDA 21 CFR Part 11-compliant.

Memobase Plus is capable of managing four different sensor types simultaneously: pH (glass and ISFET); dissolved oxygen; ORP, conductive and inductive conductivity; and chlorine.

The software provides guided, step-by-step instructions for the correct calibration procedure required by each sensor. A Live-Graph function provides visual control during the calibration, enabling appraisal of sensor condition. It also provides full traceability of all testing equipment and reference solutions. “As found, as left" measurements can be performed to assess measurement uncertainty before calibration.

Memobase Plus constantly monitors Memosens sensors and keeps logs to document the entire sensor life cycle. It maintains time stamps for adjustment and deactivation with explanations, an operating hours counter to help analyze sensor condition, and a calibration timer to help schedule calibrations. Operators can view a numerical and graphical display of primary and secondary measured values with a zoom function and a time bar.

Reports include all the information required for sensor calibration, maintenance and audit trails—including old and new calibration values, delta values, and calibration history charts with slope and zero point. Reports are subdivided into Measure, Calibrate, Sensors and Reference Solution categories for fast retrieval of specific data. A sorting and filter function helps users find data more quickly. Reports are available on the PC screen, and can be exported as a PDF document or a CSV file.

For security purposes, as defined in 21 CFR Part 11, the computer-generated audit trail function is protected from intentional or accidental modification. The audit trail tracks operator entries including operator name and ID—along with actions creating, modifying or deleting records. The entire audit trail is retrievable throughout the record’s retention period. Users cannot modify or delete audit trail information

System access and modification are allowed only by person(s) with “Administrator” rights. Access requires an electronic signature consisting of a unique Identification-Password combination. The software can be configured to force users to renew their password periodically, such as every 30 days.

Per 21 CFR, Memobase Plus is a closed system, with access restricted to only those persons designated to handle the unit or who are responsible for the contents of the recorded data.

Auto-Flushed with Success

Residual chlorine monitors and indeed, ozone monitors, pH meters and chlorine dioxide analysers have all been around a long time and it would seem unlikely that they could be improved upon greatly ……. but for some applications they have!

In 2007 a paper mill approached Process Instruments (UK) Ltd (Pi) with a problem. They had a de-inked stock that they measured pH in to control a chemical addition. The problem was that their pH sensor was coating with ink that set hard on the glass. The pH sensors were unreliable a short time after replacement and the cost of replacing the sensors monthly was prohibitive. Following a detailed survey and discussion with the customer Pi proposed an auto-flushing device that would flush the pH sensor with warm, soapy water regularly enough to prevent rather than remove build up of ink.

Two years after installation the same pH sensor continues to give reliable results with the CRIUS® 100 analyser not only controlling the pH sensor, but providing the PID control for the chemical addition.

The CRIUS® Autoflush is controlled by the analyser where user variables adjust the flush time, frequency and signal hold time.

Fortunately not all cleaning requirements are so tough and via a ‘customer consultation’ exercise (we asked them!) Pi discovered that the need to keep sensors clean is far greater than previously imagined. Since 2006 Pi has shipped approximately 50 autoflush units all using potable water to keep various sensors clean under varying conditions. Some of the applications that have benefitted from a CRIUS® Autoflush are:

• pH sensor in a de-inking plant
  
• free chlorine sensor in white water in a paper plant
  
• chlorine dioxide sensor in a food plant
  
• pH sensor in an industrial chemical plant

Video below (31 secs) shows the unit in action.


Pi has been providing instrument solutions since 1998 and supplies through Distributors, under Private Label/OEM agreements and to End Users within the Water, Waste, Chemical, Paper, Pool and Leisure industries. With offices, a laboratory and new manufacturing facilities in Burnley, Lancashire, Pi operates globally with customers in Europe, America and the Middle East. More recently Pi has received awards for innovation and has quadrupled its turnover in three years.