Rotronic HygroPalm AW1, Instruction Manual

Page 1: ...20020715 HygroPalm AW1 Portable Water Activity Indicator Instruction Manual v 3 ...

Page 2: ...Aw 25 Appendix 2 Maintenance of the ROTRONIC probes 27 Cleaning or Replacing the Dust Filter of the Probe 27 Periodic Calibration Check of the Probes 27 Appendix 3 Calibration Basics 28 Temperature Calibration 28 Humidity Calibration 28 Appendix 4 Accessories and spare parts 30 Note functions such as instrument configuration with a PC as well as the calibration of HygroClip probes separately from ...

Page 3: ...ically AwE mode same as the standard operating mode with the difference that the HygroPalm AW1 automatically detects equilibrium conditions and ends the measurement at that time The HygroPalm AW1 operates with a regular 9V alkaline battery or with a rechargeable 9V battery The optional docking station makes it possible to use the HygroPalm AW1 as a table top indicator and to power it with an AC ad...

Page 4: ...e battery the docking station can be used to recharge the battery after turning on the battery charge function see settings The RS232 port of the docking station is not used with the HygroPalm AW1 this port is used with other models of HygroPalm HygroClip Digital Probes The ROTRONIC HygroClip digital humidity temperature probes permit to take full advantage of all the features and functions of the...

Page 5: ...ing probes have a DAT 05 connector and require an adapter cable MOK 01 B5 for connection to the HygroPalm AW1 see Appendix 4 Accessories Materials in bulk HP28 insertion probe This probe is used to measure seeds barrels of pharmaceutical powders etc Shipping containers and other tight spaces SC05 miniature probe Both probes are physically the same with the difference that the AwVC DIO incorporates...

Page 6: ...by the probe with the associated engineering unit When relevant the message line provides additional information The display provides information regarding the battery status When the message Low Batt appears the instrument can typically be used for another 10 to 15 minutes Water Activity and Temperature Probe Input 1 is the only input used Engineering Unit Active Mode and Message Line Trend Indic...

Page 7: ...press briefly on the ON OFF key Press again briefly on the key to return to normal operation ON OFF Turns the instrument on or off and also controls the HOLD function This key has no effect when either the AwQuick or the AwE operating mode is running MENU Press this key to enter the Function Menu and select the operating mode etc The different menu items appear on the LCD message line Press this k...

Page 8: ...ssed When neither the AwE mode nor the AwQuick mode are running the HygroPalm AW1 returns temporarily to the standard mode x AwE mode this mode is essentially the same as the standard mode with the difference that the HygroPalm AW1 automatically detects equilibrium conditions and ends the measurement at that time by freezing the display x AwQuick mode this mode accelerates the water activity measu...

Page 9: ...erature In the above example the HygroLab will consider temperature to be at equilibrium when the rate of change of the temperature signal is less than 0 01 qC per minute Default value 0 01 qC min Press the ENTER key to record and confirm this setting The AwE mode is now active When ready to measure press the ENTER key to access and start the AwE mode Press the ENTER key again to stop the AwE mode...

Page 10: ...lm AW1 will consider temperature to be stable when the rate of change of the temperature signal is less than 0 01 qC per minute Default value 0 01 qC min Press the ENTER key to record and confirm this setting The AwQuick mode is now active When ready to measure press the ENTER key to access and start the AwQuick mode Press the ENTER key again to stop the AwQuick mode at any time and return to the ...

Page 11: ...molecules in the material structure capillary condensation formation of a solution etc Depending on the absorption process water is bound to the product with more or less strength Moisture content can include both an immobilized part e g water of hydration and an active part Water activity Aw or equilibrium relative humidity ERH measures the vapor pressure generated by the moisture present in a hy...

Page 12: ...ctly equal to the magnitude of the change of the saturation pressure ps above pure water In summary a change in temperature causes the partial pressure of water vapor above a hygroscopic product to change At the same time the partial pressure in the air above the product is practically unchanged It follows that any change in the temperature of a hygroscopic product automatically causes the product...

Page 13: ...he product with a relative humidity sensor RH 100 x Aw Because temperature is an important factor when measuring water activity the temperature of the air above the product is also monitored By definition water activity is equal to RH 100 when equilibrium has been reached At that time the product no longer interchanges moisture with the surrounding air The following uses the Rotronic AW DIO water ...

Page 14: ...ute 0 0075 qC minute in the case of product with a water activity 0 80 aw b Prior to measurements place each product sample in a disposable sample cup with the cover on Place the cups in the same general area as the probe Allow for sufficient time for the samples to come to the temperature of the probe usually room temperature A frequent mistake is to measure product samples which have been kept o...

Page 15: ...4 minutes measurements typically require about 5 minutes The difference between the AwQuick mode and the full product equilibrium is typically 0 005 aw or less The value of the dwell time can be set by the user see SETTINGS This value represents a trade off between speed of measurement and accuracy Generally a longer dwell time produces more accurate results but causes measurements to take longer ...

Page 16: ... 0 0 1 0 0 D At the end of the dwell time the display changes as follows 0 9 1 5 A w 2 4 8 1 q C Q 1 0 0 0 4 0 0 R When the projected value of Aw is stable the HygroPalm AW1 freezes the display Black rectangles to the left of the display indicate that the measurement is ended 0 9 3 4 A w 2 4 7 9 q C Q 1 0 0 0 4 5 0 S Press the ENTER key to exit this screen Press ENTER again to start a new measurem...

Page 17: ...re measurements typically require 30 to 60 minutes When ready to measure 1 Press on the ENTER key The display shows Note the numerical values are for illustrative purposes only 0 2 9 5 A w 2 4 8 3 q C E 1 0 0 0 0 0 0 R After 60 seconds the trend indicators appear both for humidity and temperature Two arrows mean stable signal as per the settings defined when selecting the AwE mode 0 6 8 4 A w 2 4 ...

Page 18: ...select Some menu items have sub items These can be selected with the UP DOWN and ENTER keys To exit the menu and return to the normal display mode press the MENU key The instrument also returns automatically to the normal display mode when no key is being pressed for some time main menu 10 sec submenu 30 sec The HygroPalm AW1 menu includes the following items x MODE x ADJUST MPT x ADJUST 1PT x SET...

Page 19: ...e Appendix 3 Humidity Calibration Procedure Please be sure to observe the following rules a Always calibrate temperature first if temperature needs to be calibrated b When calibrating temperature 2 points always calibrate at the low value first The instrument is programmed to use the low temperature value to compute the offset and the high temperature value to compute the gain T low 70 qC 158qF us...

Page 20: ...he humidity or temperature value to match the value of the reference environment For a faster change keep the key pressed down Press the ENTER key when done After pressing the ENTER key the message sure should appear on the LC display Press ENTER to confirm Next the LC display will confirm that the probe adjustment has been successfully completed At that time press ENTER to exit or MENU to return ...

Page 21: ...probe at the time the ENTER key was pressed The letters RHS are displayed on the message line Use the UP or the DOWN key to change the humidity value to match the mean value at 23qC written on the certificate supplied with the standard For a faster change keep the key pressed down Press the ENTER key when done Note in the RHS mode the software automatically compensates for the effect of temperatur...

Page 22: ... less than 0 02 RH min or qC min Signal stability is first evaluated after 60 seconds into the measurement and is updated every 30 seconds Humi Unit use the UP or the DOWN key to change the symbol used for relative humidity depends on country and language or to display humidity as water activity Accu Charge the battery charge function should always be turned off when the instrument is powered with...

Page 23: ...hat is reserved for production and service 104 unknown probe input reference was made to a non existing analog or digital probe input 105 argument error error in the number of the arguments in the command or in the value of one of the arguments 106 HygroClip communication error the HygroClip probe does not answer or is not connected 107 calibration error the difference between the probe reading an...

Page 24: ...kaline battery 12 15V AC adapter 100 mA C Tip 9 V rechargeable battery 110 mAh Max current consumption 30 mA Operating limits at electronics 0 99 RH non condensing 10 50qC 14 122qF Measured parameters water activity indication range 0 000 1 000 aw temperature indication range 99 9 999 9 qC or qF System accuracy at 23qC 73qF 0 015 aw with HygroClip probe 4 point calibration 0 2qC 0 4qF Number of pr...

Page 25: ...rison between the result of the AWQ mode and the result of the AWE mode Samples with a high water activity are particularly sensitive to the effect of a change in temperature both regarding the probe and the sample itself An inversion in the trend of temperature causes particular problems When the trend of temperature changes during the measurement a false equilibrium may appear for some time and ...

Page 26: ... the time required for a measurement at full equilibrium is obviously very much affected by any change in the temperature of the probe and sample At full equilibrium the value both aw and temperature should be stable for several minutes When measuring samples with very low water activity it may make sense to relax the definition of temperature equilibrium This should lead to results in a shorter t...

Page 27: ...ion Check of the Probes Long term stability of the ROTRONIC Hygromer humidity sensor is typically better than 1 RH per year For maximum accuracy calibration of the probe should be verified every 6 to 12 months Applications where the probe is exposed to significant pollution may require more frequent verifications Both the Pt 100 RTD temperature sensor and associated electronics are very stable and...

Page 28: ...e sensors should be carefully removed from the probe If the probe has a protective slotted cap this may be left on the probe b Air velocity at the sensor should be within the limits of 200 to 500 feet minute 1 to 2 5 meters second Any comparison between two instruments at a velocity under 200 feet minute may not be valid Air velocity above 500 feet minute may damage the unprotected humidity sensor...

Page 29: ...tacle from the calibration device x Place one fiber disc each box of standards includes 5 discs in the receptacle of the calibration device The purpose of this disc is to prevent accidental spilling of the solution inside the calibration device or on the humidity sensor x Tap the top of the ampoule so that all liquid drops to the bottom of the ampoule Snap off top and empty contents on fiber disc ...

Page 30: ...r local distributor WP 14S Sample Holder 14 mm deep for use with the AW_DIO and AwVC DIO probes WP 40S Sample Holder 40 mm deep for use with the AW_DIO and AwVC DIO probes PS14 Pk of 100 disposable sample cups for use with the WP 14S PS40 Pk of 100 disposable sample cups for use with the WP 40S EA00 SCS 0 RH humidity std SCS cert pack of 5 EA05 SCS 5 RH humidity std SCS cert pack of 5 EA10 SCS 10 ...