Operating instructions Digital handheld pressure gauge HM28
Contents 1 Description ....................................... 4 2 3 Safety details ................................... 4 Operating ......................................... 4 3.1 3.2 Switching on and off ........................ 4 Pneumatic connection ..................... 4 3.3 3.4 Operating modes ............................. 4 Configuration ................................... 6 3.5 3.6 RS 232 mode ................................... 7 Battery change .............................. 10 3.
Operating instructions d ON = On OFF = Off MODE = Select operating mode - Pressure measurement c - Min./Max. - Leak rate - Datalogging e CLEAR/ZERO = Zero setting PRINT/HOLD = Print and freeze display START/STOP = Data recording / printing SET = Select config. modes SELECT = Select config. data c d e f f Matrix display Connection for pneumatic hoses Connection for plug-in power supply unit Connection for RS 232 interface Important! Please note warning symbol in the operating instructions.
1 Description Switching off Press the OFF key, or automatic switching off 1,10 or 60 min after the last keystroke. In case of a temperature change the instrument requires at least 30 minutes to adjust to the new ambient temperature. The „LOVE CONTROLS“ handheld pressure gauge HM28 is a digital pressure measuring instrument with integrated pressure sensor for the measurement of differential, relative or absolute pressures and vacuum.
Display example Switching on Max. Range: 200 mbar Full scale error 0.05 % Normal print (differential) hold and analogue/hold zero display Normal print (absolute) and differential zero diff Notes Measuring range displayed in desired unit Accuracy class as a % of full scale reading 123.45 mbar Only with differential ====== or or relative pressure HLD 123.4 mbar models Hold, store indicated value DIF 1013.2 mbar Only with absolute 1013.2 mbar pressure mode Zero sets Diff to 0 123.
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3.5 RS 232 mode The answer is terminated with a CR - The checksum is formed from the least The HM28 can be remotely operated from a significant byte of the command string personal computer via an RS 232 interface. The automatic switching off (chapter 3.1) is inactive. Connection by means of a RS232cable.
* * * * * * * * readtemp clearmem readconfig setzero setdefault setunit_kpa setunit_mbar setunit_bar 146 CR 248 139 54 CR 91 CR 60 CR _ °C (tab)[ok] (tab)[ok] (tab)[ok] 13 * Checksum _ (tab)"Value" * Checksum * * Checksum CR (tab)"Value" (tab)Code (see decoding in table page 17) (tab)[ok] 124 CR (tab)"Value" 112 CR _ "Unit" * 230/98 _ "Unit" * Checksum (tab)"Recinterval" _ (tab)"Value" (tab)[record_stopped] (tab)[out_of_range] (tab)[record_end] * readrecord 69 CR (tab)"Ran
86 CR 87 76 80 124 125 126 129 186 187 189 233 setrecint_off setrecint_man setrecint_1 setrecint_5 setrecint_10 setrecint_20 setrecint_30 setrecint_60 setrecint_2m setrecint_3m setrecint_5m setrecint_10m * * * * * * * * * * * * 34 settempmode_1 * 57 255 162 54 252 143 39 148 1 CR 254 248 245 62 CR 240 33 CR * * * * * * * * * * * * * * settempmode_0 * setunit_mmh2o setunit_mmhg setunit_psi setunit_inh2o setunit_inhg setunit_hpa setunit_pa setunit_mpa setbaud_9600 setbaud_4800 setbaud_2400 setbaud
235 238 198 187 235 240 115 21 23 183 5 225 CR CR CR CR CR (tab)ok (tab)ok (tab)ok (tab)ok (tab)ok (tab)ok (tab)ok (tab)ok (tab)ok (tab)ok (tab)ok (tab)ok (tab)[er] Note: The character _ indicates a space * * * * * * * * * * * * Control commands/syntax setrecint_30m setrecint_60m setautooff_man setautooff_1 setautooff_10 setautooff_60 setdamp_off setdamp_on setdisrate_2.
Units Measuring rate in RS232- mode Measuring ranges up to 7 bar 10 to 30 bar 70 bar mbar bar Pa kPa hPa MPa mmH2O mH2O mmHg psi inH2O inHg x x x x x x x x x x x x x x x x x x x x x x x x x x x - -Class 0,2 20 measurements/s -Class 0,1 and 0,05 10 measurements/s Measuring rate, 2 ½ or normal mode 5 measurements/s Memory capacity max. 964 measurements Memory interval manual, 1,5,10,20,30,60 s 2,3,5,10,30,60 min Display LCD matrix, 2 lines of 16 characters Pneum.
4.2 Measuring ranges Metric Range English Range (rounded) Max. load capacity 0 ... 2.5 kPa 0 ... 10 inH2O 12.5 0 ... 7 kPa 0 ... 28 inH2O 35 kPa 140 inH2O 700 kPa 100 psid 0 ... 20 kPa 0 ... 80 inH2O 150 kPa 600 inH2O 700 kPa 100 psid 0 ... 30 kPa 0 ... 120 inH2O 150 kPa 600 inH2O 700 kPa 100 psid 0 ... 50 kPa 0 ... 200 inH2O 400 kPa 1600 inH2O 700 kPa 100 psid 0 ... 100 kPa 0 ... 14.5 psid/g 400 kPa 58 psid/g 700 kPa 100 psid 0 ... 110 kPa 0 ... 15.
6 Warning messages and faults Fault/indication ERROR OUT OF RANGE Possible cause 10% exceeding or underrunning of measuring range Over pressure applied to pressuresensor Dispatch instrument for repair Fit new battery as required Battery possibly not correctly inserted Plug in power supply unit correctly Does not switch on No power supply Instrument inaccurate Apply permissible measuring pressure Insert new battery CHANGE BATTERY Battery voltage too low No change in measurement Remedy Inaccurate
8 acceptable values acquired. In the event of a maloperation, the calibration process is interrupted and the previous calibration data are retained.
I-HM28/0501, Art. Nr. 70 792 146 Printed in Switzerland LOVE CONTROLS Division Dwyer Instruments, Inc.
