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MDM25 User’s Manual

12

 

 

 

97234 Issue 4, January 2018

MAINTENANCE

4 MAINTENANCE 

The MDM25 is designed to operate either in static ambient conditions, or in a 

fl

 owing 

gas stream.  

The sensors are designed to have excellent performance in ambient conditions. 

 

Therefore, a 

fl

 ow is not necessary to ensure that the probe is reacting rapidly to changes 

in measured conditions. 

If the sensor is installed in a 

fl

 owing sample, then it is not crucial to regulate the 

fl

 ow rate in order to ensure consistent performance, although it is preferable to avoid 

excessive 

fl

 ow rates past the sensor during operation.

The use of appropriate 

fi

 ltering for the sample conditions is always recommended – so, 

where the sample or ambient conditions may contain dust, steam or liquid water, a 

suitable mesh or sintered 

fi

 lter should be 

fi

 tted. Protection caps are also available to 

defend against the possibility of handling damage.

Care should be taken to avoid mechanical shock (impact) or thermal shock (sudden 

temperature changes). 

4.1 Probe 

Calibration

Salt solutions are commonly used for the calibration of RH sensors.  Michell Instruments’ 

calibration Control Kit is available to provide a traceable reference to verify the accuracy 

of the probe. 

 

The Control Kit can be purchased from Michell Instruments (for contact information go 

to www.michell.com).

4.2 Cleaning

The enclosure can be cleaned using a mild household detergent and a damp soft cloth 

or absorbent paper. Remove the connector before cleaning and dry off any moisture 

before reassembly.  

NOTE:  Do not use any abrasives - this may cause the LCD 

display to become obscured.

4.3 Probe 

Replacement

The probe should be returned to Michell Instruments annually for recalibration.  This 

will ensure continued traceability, and will verify that it is still performing within its 

speci

fi

 ed accuracy.

4.4 Batteries

When the battery charge indicator icon on the display is empty, the batteries should be 

replaced (see Section 2.3).  Always install 3 new batteries of the same type.

Содержание MDM25

Страница 1: ...MDM25 Hygrometer User s Manual RH Ta Abs H 53 1 21 0 C 9 7g M 3 MDM25 Hygrometer 97234 Issue 4 January 2018...

Страница 2: ...nformation when contacting Michell Instruments for service purposes Instrument Code Serial Number Invoice Date Location of Instrument Tag No Instrument Code Serial Number Invoice Date Location of Inst...

Страница 3: ...Ltd and may not be copied or otherwise reproduced communicated in any way to third parties nor stored in any Data Processing System without the express written authorization of Michell Instruments Ltd...

Страница 4: ...ment Display 3 1 2 Display Units 4 1 3 Display Settings 4 1 4 Device Settings 4 1 5 About 4 2 INSTALLATION 5 2 1 Unpacking the Instrument 5 2 2 MDM25 Accessories 5 2 3 Battery Requirements 6 2 3 1 Fit...

Страница 5: ...ndix C Analyzer Return Document Decontamination Declaration 18 Figures Figure 1 Controls and Indicators 2 Figure 2 Display 3 Figure 3 Battery Compartment Location 6 Figure 4 Probe Connections 7 Figure...

Страница 6: ...anufacturer for use with the instrument Pressure Safety This product is not suitable for use at pressures greater than atmospheric Toxic Materials The use of hazardous materials in the construction of...

Страница 7: ...llimeters oz ounce RH relative humidity sec second s T temperature Ta ambient temperature Td dew point Tw wet bulb temperature V Volts percentage Warnings The following general warnings listed below a...

Страница 8: ...ions The hygrometer is contained within a molded ABS housing with a rubber surround for drop protection sealed to IP54 standards The rubber surround allows for comfortable hand held operation and safe...

Страница 9: ...25 hygrometer are located on the front panel The probe connection to the MDM25 hygrometer is made to the top panel and the battery charger cover is located on the rear of the instrument Figure 1 shows...

Страница 10: ...attery Charge Indicator Icon displays 3 dots when full When battery icon is empty replace the batteries 2 RH Display 3 Temperature Display 4 3rd Output Display presents the selected 3rd output either...

Страница 11: ...w or condensation forms on cooling a gas This is therefore the temperature at which air becomes saturated in equilibrium with water Absolute Humidity Abs H g m3 The mass of water vapor present in unit...

Страница 12: ...al 2 2 MDM25 Accessories Filters and Protection Caps For 12mm probe For 19mm probe Slotted protection cap black Slotted protection cap black Mesh filter Mesh filter Flat SS sintered dust filter Flat S...

Страница 13: ...high energy density and long shelf life Do not mix different type of batteries All three batteries must be of the same type 2 3 1 Fitting the Batteries Unscrew the battery compartment and insert the...

Страница 14: ...directly into the connector on the top of the MDM25 Align the locating peg with the locating notch and then rotate the knurled thumb wheel until the probe is securely held in place Locating Peg Locat...

Страница 15: ...temperature Ta If using the MDM25 alongside the S503 RH calibrator adjust the display orientation to allow for the product to be read correctly when upside down If there is there is no reading on the...

Страница 16: ...5 bright DISPLAY ORIENTATION Press Press Press Press Special feature The display turns automatically when hand meter is positioned upside down To store these settings in the memory press the Menu but...

Страница 17: ...0 Steps of 5 mins from 10 to 20 AUTO OFF disabled TEMP UNITS By pressing the Up and Down Keys temperature units can be selected as either Celcius or Fahrenheit 3RD VALUE By pressing the Up and Down Ke...

Страница 18: ...ON 3 2 3 About ABOUT FIRMWARE VERSION View the firmware version and serial number of the hand meter This number relates to the hand held unit ONLY not the attached probe Press Press Press the Menu but...

Страница 19: ...mage Care should be taken to avoid mechanical shock impact or thermal shock sudden temperature changes 4 1 Probe Calibration Salt solutions are commonly used for the calibration of RH sensors Michell...

Страница 20: ...MDM25 User s Manual Michell Instruments 13 APPENDIX A Appendix A Technical Specifications...

Страница 21: ...al Connections M9 5 way binder connector PROBES Performance Measurement Range RH 0 100 RH Accuracy at 25 C 77 F Temperature 0 2 C 0 36 F Stability RH Sensor 1 RH year Response time RH Sensor 10 sec ty...

Страница 22: ...MDM25 User s Manual Michell Instruments 15 APPENDIX B Appendix B Quality Recycling Warranty Information...

Страница 23: ...ectives Full information can be found on our website at www michell com compliance This page contains information on the following directives ATEX Directive Calibration Facilities Conflict Minerals FC...

Страница 24: ...MDM25 User s Manual Michell Instruments 17 APPENDIX C Appendix C Analyzer Return Document Decontamination Declaration...

Страница 25: ...s chemicals YES NO Radioactive substances YES NO Other hazards YES NO Please provide details of any hazardous materials used with this equipment as indicated above use continuation sheet if necessary...

Страница 26: ......

Страница 27: ...use EMC requirements Group 1 Class B equipment emissions and Portable Equipment immunity and has been designed to be in conformance with the relevant sections of the following standards or other norma...

Страница 28: ...http www michell com...

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