Hanna Instruments HI 98140 Instruction Manual

Also see for HI 98140: Instruction manual Manual

Contents

Hanna Instruments HI 98140 Instruction Manual Manual pdf 11 page image

2120GLP AND RS232All the GLP data can be retrieved (if the electrode is connected) froma PC through the RS232 communication feature. The calibration dataare transferred to the PC along with measurement data (see "Datatransfer to PC" paragraph).LAST CALIBRATION DATALast calibration data are stored automatically after a successfulcalibration and they can be displayed by pressing the GLP key.to view pH calibration data• Press ALT and GLP when the meter displays pH reading.• The LCD will then display the last pH calibration date.• Press RANGE to scan remaining data, in the following order:last calibration timeelectrode offset value in mV ("OFF" appears in the lower LCD)electrode slope in mV/pH ("SLP" appears in the lower LCD)first point calibration buffersecond point calibration buffer (only if a 2-point calibration hasbeen performed).If calibration was performed with an old or dead probe, themessage "Old probe" or "Dead probe" will scroll on LCD.• The meter will then return to normal operational mode. Press ALTand GLP to escape before viewing all the data.to view mV calibration data (HI98150 only)• Press ALT and GLP when the meter displays mV reading.• The LCD will then display the last mV calibration date.• Press RANGE to scan remaining data, in the following order:last calibration timefirst calibration pointsecond calibration pointthird calibration point (only if a 3-point calibration has beenperformed).• The meter will then return to normal operational mode. Press ALTand GLP to escape before viewing all the data.GOOD LABORATORY PRACTICE (GLP)GLP is a set of functions that allows the storage or retrieval (whennecessary) of data regarding the maintenance and status of theelectrode. HI98140 and HI98150 use electrodes with a built-inEEPROM in which calibration data are read at start-up and storedafter calibration. The meter can automatically analyze the data andadvise the user if a problem is found with a clear message.PROBE LIFE VERIFICATIONAt the end of calibration, the meter checks if offset is between -30 and+30 mV and the slope between 53.5 and 62 mV/pH. If the valuesare not within these parameters, the message "old probe" scrolls acrossthe LCD. The electrode is still working, but it will be necessary to performa cleaning procedure (see electrode cleaning and maintenance para-graph) or replace it.If the offset is outside the -60 and +60 mV range or the slope isoutside the 40 to 70 mV/pH interval, the "dead probe" message willscroll across the LCD; the readings will blink on the upper LCD to warnthe user that they are not reliable.ELECTRODE IDENTIFICATIONAt start-up the meter checks if the electrode is inserted. If not themessage "no probe" scrolls across the LCD and a dashed line "----" willbe displayed in place of the reading.If the meter detects a "dead probe" the readings will blink.The meter checks the electrode only at start up. If an electrodereplacement is needed, turn the meter off before disconnecting theelectrode. Then replace the electrode and turn the meter on again.CALIBRATION ALARM TIME-OUTThe calibration alarm time-out is available only for pH calibration.It is possible to set (through setup code 10) the number of daysbefore the next required calibration procedure. User can set a valuefrom 01 to 99 days. The default value is 07. Set the parameter to"OFF" to disable this feature.When turned on, the meter checks if the time-out time has expired. If the time has run out,the message "Cal date" scrolls across the LCD.The "DATE" symbol will blink as a reminder.Alarm time-out is also signaled when viewing logged data throughthe "Cal date" message.