calibratable 4-function psychrometer ep8709
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1. ambient temperature values measured since the meter was powered on press the MAX MIN button again The text MIN will replace MAX at the right of the RH readout and both readouts will indicate the lowest values of RH and ambient temperature measured since power on To return to displaying real time RH and ambient temperature readings press the MAX MIN button a third time The text MIN will disappear from the RH readout CALIBRATING THE METER Your EP8709 was calibrated at the factory so its measurements should remain within their specified tolerance for several years However you can re calibrate the unit yourself to reassure yourself of the accuracy of readings especially after the instrument has been operated for many hours in a dusty environment To calibrate the EP8709 you must use two jars of standard calibration salt one containing a 33 solution of MgCl and the other a 75 solution of NaCl Both are available for purchase from General as part numbers SKUs HR33 and HR75 Before beginning the calibration procedure which takes at least 2 1 2 hours to complete you must disable the APO function so the instrument can remain on for more than 20 minutes To disable the APO function power on the unit in a special way by pressing and holding the DEW button while pressing the button Following is the calibration procedure 1 N Se 4 o1 With the unit powered on and the APO function disabled rotat2. decrease it to a value between 75 0 and 75 5 13 15 Store the calibration adjustment you have just made by pressing the 9 button 16 Remove the unit from the 75 salt bottle and repeat Steps 10 through 15 to calibrate the unit to the 75 reference a second time When you press the DEW and F C buttons to enter calibration mode this time the lower readout will display the following 2 Two Calibrations constitute a cycle 17 Store the calibration adjustment you have just made by pressing the 5 button The EP8709 is now calibrated to the 75 reference standard SPECIFICATIONS Temperature Measurement Range 14 to 122 F 10 to 50 C Temperature Measurement Accuracy 1 8 F 1 C Temperature Measurement Resolution 0 1 RH Measurement Range 0 to 99 9 RH Measurement Accuracy 3 from 5 to 95 RH RH Measurement Resolution 0 1 Response Time lt 80 seconds Display Size 1 7 in 43mm diagonal Current Consumption lt 15mA Battery Life 60 hours typical Dimensions of Instrument 7 56 X 2 40 x 1 57 in 192 x 61 x 40mm Dimensions of Box 7 76 X 3 66 x 1 58 in 197 x 93 x 40mm Weight without battery 3 77 oz 107g Power Source 1 9V battery included 15 OPERATING amp MAINTENANCE TIPS When the dT icon appears at the upper right of the display Fig 2 Callout A it s time to replace the 9V battery that powers the instrument although measurements w
3. CALIBRATABLE 4 FUNCTION PSYCHROMETER USER S MANUAL EP8709 Please read this manual carefully and thoroughly before using this product TABLE OF CONTENTS Introduction 2 4 Key Features 0 0ceeaee 4 What s in the Box 5 4 Product Overview 4 6 Setup Instructions 7 Install Battery 00 7 Operating Instructions 7 10 Making Basic Measurements 7 9 Tracking Min and Max Levels 9 10 Calibrating the Meter 10 14 Specifications 5 15 Operating amp Maintenance Tips 16 Warranty Information 17 Return for Repair Policy 18 INTRODUCTION Thank you for purchasing General Tools amp Instruments EP8709 Calibratable 4 Function Psychrometer Please read this user s manual carefully and thoroughly before using the instrument The EP8709 can measure any environment s ambient temperature relative humidity RH and dew point and wet bulb temperatures These measurements are typically made by three groups of users 2 e Water damage restoration contractors e HVAC R system installers and technicians e Professionals charged with monitoring and maintaining the environment of facilities such as office buildings greenhouses food and equipment storage facilities wineries freezers shipping containers computer rooms labs libraries museums and saunas The dew poi
4. E NOT RESPONSIBLE FOR TYPOGRAPHICAL ERRORS MAN EP8709 5 3 13
5. Instruments or to a General authorized service center freight prepaid and insured Acceptance of the exclusive repair and replacement remedies described herein is a condition of the contract for purchase of this product In no event shall General be liable for any incidental special consequential or punitive damages or for any cost attorneys fees expenses or losses alleged to be a consequence of damage due to failure of or defect in any product including but not limited to any claims for loss of profits RETURN FOR REPAIR POLICY Every effort has been made to provide you with a reliable product of superior quality However in the event your instrument requires repair please contact our Customer Service to obtain an RGA Return Goods Authorization number before forwarding the unit via prepaid freight to the attention of our Service Center at this address General Tools amp Instruments 80 White Street e New York NY 10013 212 431 6100 Remember to include a copy of your proof of purchase your return address and your phone number and or e mail address NOTES 19 Specialty Tools ci Instruments GENERAL TOOLS amp INSTRUMENTS 80 White Street New York NY 10013 3567 PHONE 212 431 6100 FAX 212 431 6499 TOLL FREE 800 697 8665 e mail sales generaltools com www generaltools com EP8709 User s Manual Specifications subject to change without notice 2013 GENERAL TOOLS amp INSTRUMENTS NOTICE WE AR
6. e 33 reference a second time When you press the DEW and F C buttons to enter calibration mode this time the lower readout will display the following 2 Two calibrations constitute a cycle Store the calibration adjustment you have just made by pressing the C button The EP8709 is now calibrated to the 33 reference standard Remove the unit from the 33 salt bottle 12 10 11 12 13 14 Insert the EP8709 upside down in the opening of the 75 salt bottle after removing the bottle s cap The fit should be tight with no air leaking into the bottle Leave the unit upside down in the 75 salt bottle for at least 40 minutes Check the upper RH readout without turning the unit right side up or removing the sensor structure from the bottle If the reading is between 74 5 and 75 5 the meter is operating within its RH specification Remove the EP8709 from the 75 salt bottle If the reading is not between 74 5 and 75 5 the unit is out of calibration at this reference point To adjust its calibration press the DEW and F C buttons at the same time to enter calibration mode The lower readout will switch from displaying ambient temperature to showing the following oe 1 If the reading is less than 74 5 press the F C button as many times as necessary to increase it to a value between 74 5 and 75 0 If the reading is greater than 75 5 press the DEW button as many times as necessary to
7. e the sensor protection cap to open its three vents and expose the humidity sensor to the environment Turn the unit upside down and insert the sensor structure in the opening of the 33 salt bottle after removing the bottle s cap The fit should be tight with no air leaking into the bottle Leave the unit upside down in the 33 salt bottle for at least 40 minutes Check the upper RH readout without turning the unit right side up or removing the sensor structure from the bottle If the reading is between 32 5 and 33 5 the meter is operating within its RH specification Remove the meter from the 33 salt bottle and proceed to step 10 If the reading is not between 32 5 and 33 5 the unit is out of calibration at 11 o 7 8 9 this reference point To adjust its calibration press the DEW and F C buttons at the same time to enter calibration mode The lower readout will switch from displaying ambient temperature to showing the following oe 1 If the reading is less than 32 5 press the F C button as many times as necessary to increase it to a value between 32 5 and 33 0 If the reading is greater than 33 5 press the DEW button as many times as necessary to decrease it to a value between 33 0 and 33 5 Store the calibration adjustment you have just made by pressing the C5 button Remove the unit from the 33 salt bottle and repeat Steps 2 through 7 to calibrate the unit to th
8. ear at the right of the RH readout To unfreeze the display and resume showing real time readings press the HOLD button again This will cause HOLD to disappear from the RH readout Pressing any button turns on the green backlight for 10 seconds To extend the life of the 9V battery powering the EP8709 the unit s Auto Power 8 Off APO function will automatically shut down the instrument if no front panel buttons are pressed within any 20 minute period To disable the APO function power on the unit in a special way by pressing and holding the DEW button while pressing the C button The LCD will confirm that you are disabling the APO function by displaying its complete set of icons see Fig 2 until you release the DEW button The APO function will be enabled the next time you power on the unit in the normal way To power off the EP8709 press and hold the C button for at least 3 seconds TRACKING MIN AND MAX LEVELS After being powered on the EP8709 automatically operates in Recording mode for the purpose of tracking maximum and minimum RH and ambient temperature measurements To display the maximum RH and ambient temperature values measured since the meter was powered on press the MAX MIN button once The text MAX will appear at the right of the RH readout and both readouts will indicate the highest values of RH and ambient temperature measured since power on To display the minimum RH and
9. ill remain valid for several hours after the icon first appears To replace the battery follow the instructions on page 7 To prevent dust and moisture from degrading the performance of the humidity and temperature sensors after each measurement session rotate the sensor protection cap to close its three vents Do not operate the EP8709 in the presence of a flammable or explosive gas or near an arc welder or induction heater After subjecting the unit to a large change in ambient temperature wait at least 30 minutes before making measurements to guarantee the accuracy of readings Remove the battery when storing the unit or when you do not expect to use it for an extended period of time months rather than weeks Do not drop or disassemble the EP8709 or immerse it in water WARRANTY INFORMATION General Tools amp Instruments General s EP8709 Calibratable 4 Function Psychrometer is warranted to the original purchaser to be free from defects in material and workmanship for a period of one year Subject to certain restrictions General will repair or replace this instrument if after examination the company determines it to be defective in material or workmanship This warranty does not apply to damages that General determines to be from an attempted repair by non authorized personnel or misuse alterations normal wear and tear or accidental damage The defective unit must be returned to General Tools amp
10. into the wired socket inside the compartment The terminals of the battery and the socket mate in only one way with the smaller male terminal plugging into the larger female terminal 3 Replace the battery compartment cover and tighten the screw to secure it to the housing OPERATING INSTRUCTIONS MAKING BASIC MEASUREMENTS Before making any measurements rotate the sensor protection cap with your thumb and index finger so its three vents are open to the ambient environment from both the front and back Press the button to power on the meter The dual displays will immediately begin reading out humidity and 7 ambient temperature measurements made by the sensors at the top of the unit To display the dew point temperature instead of ambient temperature on the lower readout press the DEW button The reading will be accompanied by the symbol DEW at its left To return to displaying ambient temperature press the DEW button again To display the wet bulb temperature instead of ambient temperature on the lower readout press the WBT button The reading will be accompanied by the symbol WBT at its left To return to displaying ambient temperature press the WBT button again By default the EP8709 displays ambient dew point and wet bulb temperatures in C To switch to F press the F C button To hold a pair of readings RH ambient dew point wet bulb temperature press the HOLD button The text HOLD will app
11. ion cap a 9V battery and this user s manual PRODUCT OVERVIEW Figure 1 shows all of the controls indicators and physical structures on the front top and bottom of the EP8709 Figure 2 shows all text and icons that could appear on the unit s LCD Familiarize yourself with the positions and functions of all buttons structures and icons before moving on to the Setup Instructions and Operating Instructions 4 EP8709 moc l Fig 1 The EP8709 s controls indicators and physical structures A Humidity and temperature sensors B LCD C amp Power on off button D F C button E WBT wet bulb temperature button F DEW button G HOLD button H MAX MIN button Battery compartment DOB OO ojwer ir Fig 2 All possible display indications and their meanings A Low battery icon B Data hold indicator C Maximum reading indicator D Minimum reading indicator E C indicator F F indicator G Wet bulb temperature indicator H Dew point temperature indicator Temperature readout J Relative humidity RH readout SETUP INSTRUCTIONS INSTALL BATTERY 1 The meter s battery compartment Fig 1 Callout I is accessible from the bottom of the unit Use a Phillips head screwdriver to loosen the single screw in the back of the unit that holds the yellow battery compartment cover in place Set the cover and screw aside 2 Plug the included 9V battery
12. nt is the temperature below which the water vapor in a volume of air at a given constant barometric pressure will condense into liquid water at the same rate at which it evaporates Condensed water is called dew when it forms on a solid surface Another way to think of the dew point is as an air saturation temperature associated with relative humidity RH A high RH value indicates that the dew point is close to the current ambient air temperature At 100 RH the dew point temperature is equal to the ambient temperature because the air is completely saturated with water The wet bulb temperature is the temperature that a volume of air would have if it were cooled to saturation 100 RH by the evaporation of water into it with the latent heat coming from the volume of air It is the lowest temperature that can be reached under current ambient conditions by the evaporation of water only The wet bulb temperature is the temperature you feel when your skin is wet and exposed to moving air as opposed to the actual air temperature the dry bulb temperature The EP8709 is powered by one 9V battery included KEY FEATURES e Jumbo backlit display with 2 line readout e Field calibratable using optional 33 and 75 salts e Data hold and Min Max functions e F C switch e 20 minute Auto Power Off function e Low battery indicator WHAT S IN THE BOX The EP8709 comes fully assembled in a box along with a sensor protect
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