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User`s Manual

1. Controls left to right First set DATA SOURCE switch to AUTO STEP If 55 252 optioned Next flip RUN STOP switch from RUN to STOP to reset to STEP i 1 STEP DURATION Allows selection of duration at each step level Intervals are 3 75 m 7 3 m 15 m 30m ihr 2 hr 2 MAN ADVANCE Push button to increment to next step level 3 CLOCK Green Flashing LED lit when STEP clock is running 4 RUN STOP Toggle Switch STOP resets to STEP 1 RUN activates timer clock according to DURATION knob 5 STEP 1 8 LED shows active STEP 3 digit LCD shows what the COMMAND RH is set to A 20 turn adjustment via small screwdriver supplied in kit allows adjustment of each step from 0 100 Z RH Insert above each LED DATA SOURCE Switch selects between Auto Step and Computer Interface for VAPORPAK and LCD COMMAND RH display 11 PROGRAM CONTROL UNIT UNDER COMPUTER OR 55 2352 SERIAL CONTROL The PCU must be set to COMPUTER on DATA SOURCE switch setting This allows the serial D A A D system to read and output its signals to the VAPORPAK and the PCU LCD display also When in this mode the VAPORPAK current internal RH probe reading is read into the computer as channel 1 and up to 3 each 0 5 volt user channels are also available to plot and or log to disk This configuration enables a totally automated calibration platform exist for up to 3 customer sensors The PCU has a power off memory system that remembers most
2. 0004 0094 0510 0502 0004 0004 0004 0510 0502 0004 0004 0004 220 0502 0004 0004 0004 Fi COMMAND VALUE F2 SAMPLE F3 AVERAGE F4 CHANNELS F5 DISK LOG F10 EXIT Note that Command A is the D A output to the VAPORPAK the units are in millivolts on the display screen O to 5000 millivolt range 12 PCU DEMO UTILITY SOFTWARE continued 7 To change a command value to the chamber hit Fi then type the voltage you want Example 5 is 50 RH 842 is 84 2 7 RH Note that Input 1 is the actual chamber RH value expressed in millivolts 1000 mv on screen equals 100 0 chamber RH 9 The other Commands Function Keys are similar and fairly self explanatory 10 Consult the available PCU support guide for programming details AVAILABLE PC DRIVER PACKAGES At present two IBM PC based logging and control packages are offered Described above is the Utility called ADLOGR It is a Pascal program for which we provide source code for customer modification etc Also provided is an advanced driver called PCU which allows up to 1 programmable command RH steps to the VAPORTRON VAPORPAK system Various plotting plot scaling signal averaging and logging options are featured 15 START UP 1 Unpack unit from carrying case amp inspect it for an intact and mostly blue desiccator tube on the back Make sure the hoses going to the tube are not pinched or restricted Move the tube left or right as needed 2 Us
3. a 0 2 RH or a dewpoint of approx 40 C Finally the air is again mixed thoroughly with the chamber air upon its entrance Because of the servo nature of this system the chamber responds rapidly to either a change in setpoint or a sudden change in chamber humidity loading The servo pumps provide an ample overdrive capability such that only 1 2 minutes are required for most step changes in command value At the extreme ends gt 10 and gt 90 RH the system can take 5 10 minutes to reach the desired humidity This is due to reduced drive differential and chamber container and any contents surface uptake outgassing at each end of humidity extremes Typical control errors deviation from setpoint are 5 RH from 30 to 80 5 RH setpoint to around 2 5 error at the ends of the controlled range 3 to 97 RH The control servo is an asymmetric proportional type with a cycle time of approx 1 sec To allow for near 100 5 RH at ambient chamber temperature the vapor saturator is electrically heated when the command setpoint exceeds 90 RH GOMER TPA GAPDH CORE KIOL REF SENSOR Rotronics H 31 OEM SENSOR Vaisala HMP 35A HMD 30 UB OEN RH error amp amp servo PWN generator renote manna l setpoint 8 166 z Humidity Flow Diagram CONTROLS SWITCHES AND OPERATION IDENTIFICATION OF CONTROLS left to right on panel Main POWER switch Displays Temp and RH but no control O
4. BUCKRESEARCH INSTRUMENTS L L C CHAMBER PORT MODEL H31 PORTABLE HUMIDITY CALIBRATOR POWER CONTROL toa Bat VAPORPAK H31 PORTABLE HUMIDITY CALIBRATOR Users Manual 3 93 The 25 31 humidity calibrator is intended for rapid determination of a field sensor temperature and or humidity functionality It can also be used for sensor linearity tests as well as probe drift studies We certify this system using ASTM methods for a temperature accuracy of 1 0 Deg F or better from 68 Deg F to 90 Deg F The RH section is calibrated to an average accuracy of better than 1 RH from 11 RH to 97 RH 7 points taken Over this range a maximum error of 1 5 RH is possible at any given point The unit can generate humidity in the range of 5 to 95 RH reliably with a 0 2 RH stability Typical settling time is lt 1 minute with a 5 minute maximum near the low and high RH limits The VAPORPAK H31 is configured with a standard port size of 25 mm diameter with a fitted compression gasket For other non 25 mm sensors and probes split rubber stoppers and non hygroscopic clay are supplied for sealing around the port opening This unit is battery operable for around 3 hours with both POWER AND CONTROL switches enabled and operates for approx 5 hours with the POWER switch on and operated in monitor mode i a VA be Si 5 uct VAPORPAK Model H31 Portable Humidity Calibrator General Specifications Size 10 wi
5. HOOTING k kX In normal operation the control system will respond quickly to bring the RH reading to very close to the dial or COMMAND setting If the pumps run for a long time and or the RH reading does not quickly settle in it could be caused by the following CHAMBER TOO MOIST OR TOO DRY S s5 5 1 Leaks in or near the chamber door or through rubber port gland or rubber stopper check and apply clay or tape shut 2 Abnormally cold or hot chamber temperatures bring chamber close to ambient temperature see if control improves CHAMBER TOO MOIST NO CONTROL S 3 Condensation on chamber walls open chamber wipe walls with dry cloth allow to air dry for 5 10 minutes 5 Desiccator cartridge used up all pink or grey in color or has become physically disconnected from the chamber hoses Note that the system can actually work without the dryer connected but the chamber will be limited to around whatever the prevailing room humidity is and above 6 Hygroscopic load Some materials have TREMENDOUS water capacity in the vapor phase eg Nylons PVC plastics and woods etc remove any objects you suspect could be too hygroscopic CHAMBER TOO DRY NO CONTROL 7 No liquid water in saturator vessel check back sight glass and tilt cabinet front to back to confirm the water level 8 Cabinet of VAPORPAK unit too cold Allow system to run in th
6. If the reading is off simply adjust the command a little to get the exact RH you want 8 If all this goes well then insert a RH Temp probe to be tested calibrated and do the same thing as before The chamber might take a bit longer to stabilize since the DUT or probe might have some hygroscopic surface or residual moisture 9 Don t expect the Temperature readings to move or converge very quickly because the thermal mass of the DUT or test probe will limit how fast the small circulator fan can equilibrate the probe tip to the actual chamber temp It might take 5 or 10 mins to converge but this is important due to the RH Temperature relationship of the water vapor physics For nominal accuracy you should have no more than 0 2 Degree C difference or gradient between the DUT and the chamber Temperature display Discounting of course the static error between the two thermometers 10 If all these steps can be reached then the rest of the calibration process can be followed from the operation amp usage section of the user s manual
7. N AC green LED Blinks when on AC adaptor DC 12 V LOW BAT red LED Glows near end of NI CAD charge level CONTROL power switch Enables humidity control servo RH SET dial Setpoint for humidity range 0 to 100 10 turn RH and TEMP LCD DISPLAYS Display units and tenths units UNITS select switch Deg C or F Most accurate 70 to 90 F CHAMBER PORT 25 mm dia by approx 110 mm typical depth ANNUNCIATOR internal beeps when chamber arrives at setpoint General Operation The VAPORPAK chamber is designed to generate an optimum environment for calibration of solid state type polymer and other sensors that will physically fit inside the 25 mm diameter working cavity By providing a high aspirating airflow past the internal reference sensor AND the sensor to be calibrated an accelerated equilibrium of both temperature and humidity vapor can be realised It should be noted that due to the extremely fast and linear response of the internal polymer probe the chamber can be made to very rapidly follow a new command that is dialed in THIS CANNOT BE SAID FOR ALL SENSORS THAT ONE WILL ENCOUNTER DURING ATTEMPTED CALIBRATIONS For this reason we advise using caution especially when attempting calibration of a sensor or probe for the first time The VAPORPAK system will produce a short high pitched beep when it has first arrived to anew setpoint as dialed in or programmed in via the rear panel connector This means that the internal re
8. de X 10 depth X 3 75 height 255 X 255 X 95 mm Weight 4 6 Lbs 2 1 Kg Power 12 VDC at 5 Watts max internal 6 V Ni Cad power Temperature Range Operation 10C to 40C Storage 0C to 50 Accuracy Temperature 0 5 C 20 to 32 C Resol 0 1 Accuracy Humidity avg lt 1 RH 11 to 97 RH 1 5 max Humidity accuracy valid from 20C to 30C air temp 2 INDEX Subject Photo and General Description Photo of Front and Back Panels Specifications Index Humidity Control System Description Humidity Flow Diagram Controls Switches and Operation General Operation Typical Use in Calibrations Operating Information Contd SERVICE TROUBLESHOOTING Calibration Procedures PCU Program Control Unit Panel and Operation PCU Under RS 232 Operation PCU Continued Desiccant Technical Product Description Appendix Design Philosophy Statement Calibration Record r w Q Bis ee ey Se a m m as Humidity Control System Refer to following flow diagram on page 06 The VAPORPAK humidity control scheme is essentially a refere
9. e 90 RH continuously A temporary bias condition can result which may affect the internal reference polymer by approx 1 RH for the following 1 to 2 hours 7 Operating Information When operating the system at very high RH levels gt 90 it is important to realize that gradients in temperature ie cold Surfaces can cause condensation of liquid water on that surface When this occurs attempting to maintain or increase the RH setting will only cause more condensation and the actual air volume humidity will remain the same If there are no problems with temperature gradients etc a VAPORPAK chamber will typically achieve a 94 to 97 RH level within about 5 to 7 minutes Condensation problems can be verified by commanding a 10 or more RH step setting temporarily and watching if the RH display freezes or holds at the previous high RH reading for a long time before responding to the new setpoint evidence of liquid puddling as the system waits to evaporate liquid water from the walls etc Shut off the CONTROL switch temporarily when opening chamber door to minimize mixing with ambient air and RH over underload Water Level and Service Normally a visible water line should be seen when observing the round sight glass at the rear panel If no liquid can be seen then water should be added The water tank is accessed by removal of RED RUBBER CAP NEAR TOP REAR CENTER Add distilled water slowly with a small syringe Typically add
10. e power on only no control for a period of time 9 Hygroscopic load See item 6 remove suspect material NO CONTROL 10 CONTROL switch not activated check that it s pressed on 11 Low battery condition connect charger or other 12 VDC 3 A 12 Electronic failure consult technical documents or factory CALIBRATION OF INTERNAL REFERENCE PROBE The VAPORPAK internal reference probe has been initially factory calibrated against ASTM and possibly NIST referenced standards See details in appendix If it is desired to provide another prime calibration or reference check several possible avenues are possibles i Calibrate against a trusted reference probe using the VAPORPAK as a mixing calibration vessel Use only Rotronics Vaisala 2 Calibrate against a reference chamber by placement of the entire VAPORPAK inside the reference and operate passively 3 Remove the reference sensor and calibrate against either a primary standard or reference salt in an external chamber To access the reference sensor remove the top cover and locate the sensor using the picture below see arrow To remove reference sensor probe remove phillips holdown 93 screw grommet assy and gently pull out on probe and or sensor case housing Back SPan top and ZERO bot Adyustments Interna Reference Sensor ron The calibration pots will be labeled as either 2 and 5 or Dp and W for the respecti
11. ference sensor is stabilized within 1 RH Depending on the type condition and temperature of the sensor that is being calibrated we advise allowing a period of time from 2 minutes up to 30 minutes before either adjustment or recording output of the Device Under Test D U T Typical Calibration Procedure for RH sensors Initially place the sensor to be calibrated inside the VAPORPAK chamber port and seal the opening such that it is leak tight Use the sealing clay a rubber stopper which has been bored to the correct probe diameter or plastic electrical tape etc Allow approximately 5 to 10 minutes for sensor temperature stabilization with only the POWER switch active on the VAPORPAK Normally it is advised to establish the zero or offset value at a low RH such as 20 to 30 5 RH CONTROL on and SETPOINT adjusted on VAPORPAK Once the zero is made on the D U T proceed to an upper RH of 75 to 90 and allow a sufficient time for the D U T to stabilize in output then adjust the gain or span Since practically all sensor electronic combinations exhibit a degree of zero span interaction it is advisable to repeat the zero span steps at least once to ensure a proper transfer of calibration If the amount of either zero or span adjustment is small then reiteration of the calibration steps can be minimised or dropped HIGH RH CONDITIONS For maximum accuracy avoid operating the VAPORPAK system for more than a few hours abov
12. ing a syringe or attached plastic filler add about 10 or 15 cc ml of distilled water to the water tank Recap the rubber top when done Verify that the water line is visible in sight glass in rear of Vaporpak Exact level is not critical but water in the lower to mid glass range is best 3 Plug in the charger adaptor into the rear connector and ensure that the green ON AC lamp is lit on the front panel You can leave the charger on for lab use or just leave it connected overnight for next day s offline use 4 Turn on the POWER switch amp listen inside the test chamber for a whirring sound from the rear This is the circulating fan and it MUST be operating 5 Let the unit run for a few minutes with the front port open See that the Temp and RH readings are approximately right for the room conditions abnormally high RH means that liquid is in the chamber and it must be blown out with dry air or wicked with a paper towel very gently until the RH comes to what room RH should be 6 Next put a rubber stopper in the front fitting and turn on the CONROL switch Set the RH command dial for a low reading like 20 RH You should hear the pumps run and the chamber should drop to 20 and hold it within 0 5 or better 7 Similarly test the high range by dialing the Command knob several turns to say 70 to 75 RH The chamber should rise up to near the command and within a few minutes be again within about 1 2 of the command
13. nce based closed loop servo demand flow network The working volume 0 1 L or approx 6 cu in is basically a highly turbulent mixed constant temperature atmosphere The present relative humidity is sensed by a high grade fast response polymer type reference sensor located approximately in the center rear 1 3 of the chamber The RH signal is compared by an error amp processor to either a manually operable front panel adjustment knob setting 10 turns or to an external 0 1 volt presumably via computer DC setpoint Setpoint resolution is 0 1 RH via the front panel dial knob If the chamber RH compares lower than desired a proportional PWM pulse width modulation signal is output by the controller to a power transistor which drives a small magnetic diaphragm pump PW The pump draws chamber air pumps it through an air saturator vessel and outputs it back into the chamber The output is vented directly into a 5 lpm internal circulator fan such that rapid molecular mixing occurs inside the chamber working volume Conversely if the reference sensor senses a humidity that is moister than the present setpoint a PWM error signal is output by the controller to another transistor which in turn powers a separate dry pump PD The PD pump flow is essentially in parallel with the wet side but they do not operate at the same time The dry side pump feeds chamber air into a calcium carbonate cylinder on back panel exterior which dries the air to
14. of the previous setup configuration as well as the last RH command value When the PCU is powered on even if it is not connected to a computer the last used RH will appear on the LCD readout on the front panel PCU DEMO UTILITY PC SOFTWARE OPERATION To operate under serial interface do the following 1 Connect the DB 25 female connector to the Host computers COM 1 or COM 2 port Use a 25 pin to 9 pin adaptor for a laptop etc 2 Insert 3 5 inch 720 K 21561106 diskette with PCU label 3 The software package will run on IBM compatible PC XT AT 3864 or 484 machines 4 Log onto the correct drive type ADLOGR lt any file name gt lt Com n gt and enter You must use a file name for logging any output you might want to record from the chamber or the analog inputs The default COM port is 1 so the lt COM n gt entry is optional 5 A Screen similar to the one shown below should appear DIGILOG INSTRUMENTS VAPORTRON HUMIDITY SYSTEM Serial Program Control Unit Display Screen Average 1 Reads Send Data Every 1 Seconds NOT Logging to Disk TIME COMMAND A INPUT 1 INFUT 2 INPUT 3 INPUT 4 0510 04977 0004 0004 0004 0510 0502 0004 0004 022024 0510 0502 0004 0004 0004 0510 0502 9004 0004 0004 0510 0502 0224 0004 0004 9510 90592 0004 2224 2204 0510 0502 0004 0004 0004 05340 0507 0004 0004 0004 0510 0502 0004 0004 0004 0510 0502 0004 0004 0004 0510 0502 0004 0004 0004 0510 0502 0004 9004 0004 0510 0502 0004
15. only 10 cc of water WARNING IF THE WATER LEVEL IS OVERFILLED SEE ROUND WINDOW AT BOTTOM REAR PANEL LIQUID WATER CAN BE INADVERTENTLY PUMPED DIRECTLY INTO THE CHAMBER WORKING VOLUME BE CAREFUL Desiccant Service The desiccator cartridge on the rear panel is filled with a commercial Calcium Sulfate granule charge A colbalt chloride indicator is used to visually show when the desiccant is depleted blue dry pink or grey spent Replenish desiccant when edge of pink color approaches 2 cm 1 inch from the LEFT end of drying tube line on rear of instrument use only DARK BLUE ultra dry desiccant see attached desiccant product data sheet for re charging instructions page 14 When re filling the dryer tube use a small funnel pack desiccant down to avoid large air pockets The rate of desiccant usage is HIGHLY dependent upon type of operation encountered A typical range could be a cartridge used each day under continuous VAPORPAK up down cycling up to a month operating time under steady state setpoints with no chamber leaks Basically it should be remembered that desiccant is ONLY used when the VAPORPAK is CHANGING the humidity in its chamber cavity To preserve the maximum desiccant life avoid VAPORPAK operation CONTROL switch on with the chamber door open except for short peroids when changing sensors Keep covers on desiccator cartridge if it is stored while NOT connected to the VAPORPAK system hoses 8 TROUBLES
16. ve dry and wet adjustments If using a transfer probe operate the VAPORPAK for at least 10 minutes at each cal point shut off CONTROL when making the pot adjustments to avoid confusion If calibrating against salts follow ASTM guidelines and allow at LEAST 30 minutes at each point for stabilization In all cases set the dry or zero first then the wet or gain See text on page 07 above about calibration procedures in general If the VAPORPAK reference probe is removed re tape with teflon thread tape when re installing in chamber and or ensure that sealing O ring is seated against probe base Always calibrate in very stable temperatures or in a calibration room LO COMMAND HUMIDITY Z RH PROGRAM CONTROL UNIT PCU Description and Operation Model PCU and PCU RS232 described The PCU is an interface and automatic step controller for automating the RH commands of any model VAPORTRON VAPORPAK chamber The RS232 option when installed allows computer control via an RS 232 data conversion mocule The PCU plugs into the rear panel of a VAPORPAK chassis VIA a micro and stereo mini male plug pair The PCU is powered from the VAPORPAK 12 VDC adaptor charger When the PCU is connected to the VAPORPAK rear connector RH command data is automatically routed into the chamber front panel dial settings are ignored NOTEs THE VAPORPAK MUST BE LINE POWERED FROM THE 12 VDC BATTERY CHARGER WHEN OPERATING THE PCU ACCESSORY

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