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8758
Operation Manual
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MRC 8758, 8778 Operation Manual

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Page 1
OPERATION MANUAL
HEAT INDEX WBGT METER
Model:
8758 8778
8758
8778
Page 2
INTRODUCTION
The applications of the heat index can be in construction, iron and steel foundries, bricks-firing plants, glass facilities, boiler rooms, mining sites, army training, marathon, beach activities and so on.
Features:
Direct measurement of the radiation effect with a brass black ball. Adjustable WBGT alarm threshold Audible beeper for heat stress monitoring Sensor protecting mechanism Easy self calibration for humidity PC connect for data analysis
1
Thank you for purchasing the Heat Index WBGT meter. The handy meter measures air temperature, globe temperature, and humidity to give heat stress index for using in control of physical activity in hot environment to limit the danger of heat­related injuries
(See appendix)
Page 3
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CONTROLS AND INDICATORS
LCD display
Function Keys
Turn on and off the meter Enter alarm setting mode
Select digit in setting mode
Exit from setting mode Select display mode Shift IN/OUT mode Increase value in setting + Set as non-sleep
o
+ Select C or F + + Enter RH calibration
o
Symbol indication
WBGT Wet Bulb Globe Temperature TG Black Globe Temperature TA Air Temperature % Relative Humidity C/F Celsius/Fahrenheit IN Indoor (no sun) OUT Outdoor (full sun) Low battery indicator DP/REC Vain icons in these models.
NEX TNEX T
MOD EMOD E
MOD EMOD E
MOD EMOD E
NEX TNEX T
NEX TNEX T
MOD EMOD E
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IN/OUT switch To measure WBGT without or with direct sun exposure under IN/OUT modes, hold down for more than 1 second to switch.
Select Unit Press and simultaneously in
o
measuring mode to select C or
o
F.
3
OPERATING INSTRUCTIONS
MOD EMOD E
MOD EMOD E
NEX TNEX T
MOD EMOD E
1. POWER ON/OFF
Press to turn on and turn off the meter. All indicators are shown on
the LCD when power on, and then enter measuring mode.
2. MEASUREMENT
Slide down the protecting sheath of sensor before measurements.
Pull up to protect sensor Design patent pending
Select display mode
The meter measures TA(Air Temp), TG (Globe Temp.), RH (Relative Humidity), and calculates WBGT. Press to select modes. An icon shows on the top to indicate the current operation mode. (Fig. A)
Fig. A
Page 5
3. ALARM SETTING
The meter features audible alarm
to give warning for possible heat stress in the environment. When WBGT value reaches the alarm threshold, the value starts to blink with continuous beep(about 70 dB). The alarm stops when measured value falls below the threshold or the meter is turned off.
The alarm threshold is adjustable for different applications. Hold down for 2 seconds to turn on the meter and enter alarm setting. The current setting displays with a blinking digit. Press to increment the value and to select digit. After new alarm threshold is set, press for 2 seconds to return to measuring mode.
The setting range is 20.0~37.2 C (68.0~99.0 F). "OUT" will show if setting is out of range. (Fig. B)
o
o
MOD EMOD E
NEX TNEX T
NEX TNEX T
Fig. B
4
4. BATTERY REPLACEMENT
appears on the LCD when battery
voltage gets low. To replace battery by opening the compartment on the rear of the meter.
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5
Unscrew the black globe with sensor sheath (see pic. A) before calibration.
Follow the illustration on page 7 to recap sensor sheath after completing calibration.
Pic. A
The meter can be calibrated on the humidity by end users with 33% and 75% salt solution. The ambient condition is recommended to be at
o
23+/-2 C and stable humidity. Users can terminate the calibration anytime by turning off the meter.
RH CALIBRATION
6. TRIPOD MOUNTING The meter can fit on a tripod for long
time monitoring. A built-in thread is on the rear side of the meter.
5. AUTO POWER OFF
The meter turns off automatically
after 20 minutes non-operation. To override the function, hold down and for 2 seconds to turn on the meter. The LCD will display “n” and then enter measuring mode. (Fig. C)
MOD EMOD E
Fig. C
Sensor probe
Sensor connector
Black globe with sensor sheath
Page 7
Note:
The RH value difference between the meter display and calibration standard should be within +/-0.3%, otherwise it is a failed calibration.
The blinking “7X.X%” shows on the screen and meter is now calibrating. Wait about 60 mins.until blinking stops ,it means the calibration is completed and meter returns to measuring mode.
6
75% calibration
After 33% calibration, plug the sensor probe into 75% salt bottle, then press for 2 seconds to start.
MOD EMOD E
33% calibration
Plug the sensor probe into 33% salt bottle( Pic A1),hold down , ,and buttons for 2 seconds to power on the meter until blinking “3X.X%” appears. Meter is now calibrating, and will finish in about 60 mins. when the value stops blinking.
Note:
Strongly recommend to use one hand to press one button, and use two fingers of the other hand to press two buttons simultaneously . This is easier for you to operate 3 keys.
MOD EMOD E
NEX TNEX T
Pic.A1
Salt solution
Page 8
CAUTION:
Reassemble the globe with caution by fitting the pin (Pic. B) into the connector (Pic.C). It helps to position by targeting
the screw holes on the sheath and the meter. Incorrect installation may damage the sensor.
Sensor pin
Sensor connector
Pic.B
Pic.C
Important:
Screw holes for targeting to assemble the globe.
Pic. D
? Error message on the display
E2: The value is under range. Improper sensor installation. E3: The value is over range. E4: The value is in error because of the original data. Improper sensor installation. E11: RH calibration error. Do the calibration again. E32/E33: Circuit error. Return to the vendor for repair or replacement.
? Power on but no display Check whether the batteries are in good contact and correct polarity, or take out the batteries for one minute and reinstall and retry.
? Calibration failure
a.Check the battery voltage or replace with new batteries. b.Check whether the sensor is well plugged into the salt bottle and no air comes in. Check ambient condition.
TROUBLESHOOTING
7
Page 9
8
RS232 INTERFACE
The meter can do PC link for
data analysis
on-line logging and via RS232 interface and software. The protocol is as follows.
B.Format (Transmitting ASCII code by every
second while meter is on.)
Wxxx.xC(F):Txxx.xC(F):Txxx.xC(F) :Hxx.x%LRCCRLF
Note: The 1st value is WBGT, the 2nd is
TA, the 3rd is TG, and the 4th is RH.
A.9600 bps, 8 data bits, no parity.
SPECIFICATION
8758 8778
Black ball size
40(D)x35(H)mm 75(D)x75(H)mm
Air Temp. range
0~50℃ (32~122℉)
Air Temp. accuracy
±0.6℃
Globe Temp. range
0~80℃ (32~176℉)
Indoor
±2℃ (15~40℃) ±2.5℃ (Others)
±1℃ (15~40℃) ±1.5℃ (Others)
Globe
Temp.
accuracy
Outdoor
±3℃ (15~40℃) ±3.5℃ (Others)
±1.5℃ (15~40℃) ±2℃ (Others)
WBGT Temp. range
0~50℃ (32~122℉)
WBGT Formula
Indoor/Outdoor and no sun:
WBGT=0.7WB + 0.3TG
Outdoor and full sun:
WBGT=0.7WB + 0.2TG + 0.1TA
RH range
0~100%
RH accuracy
±3% (10~90%RH)
±5% (other range)
Resolution
0.1℃/℉, 0.1%RH
Response time
15 seconds typical
Operating condition
0~50℃, 0~95% RH
Storage condition
-20~65℃, 0~95% RH
Meter size
40(H)x48.7(W)x254(L)mm – 8758 75(H)x75(W)x278.2(L)mm – 8778
Battery life (without beep)
1000 hours (Alkaline) 250 hours (General purpose)
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MATERIALS SUPPLIED
Meter 2pcs AAA batteries Operation manual Plain box packaging
This package contains:
Optional accessory:
33% calibration salt (VZHR33AZ) 75% calibration salt (VZHR75AZ) RS232 cable and software
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WARRANTY
The meter is warranted to be free from defects in material and workmanship for a period of one year from the date of purchase. This warranty covers normal operation and does not cover misuse, abuse, alteration, neglect, improper maintenance, or damage resulting from leaking batteries. Proof of purchase is required for warranty repairs. Warranty is void if the meter has been opened.
RETURN AUTHORIZATION
Authorization must be obtained from the supplier before returning items for any reason. When requiring a RA (Return Authorization), please include data regarding the defective reason, the meters are to be returned along with good packing to prevent any damage in delivery and insured against possible damage or loss.
Page 11
APPENDIX
PERMIS SIBLE HEAT EXPOSURE THRESHOLD LIM IT
Source: ACGIH 1992(The American Conference of Governmental Industrial Hygienists)
WBGT INDEX AND PHYSICAL EXERCISE
Value:WBGT
Recommendations to heat exposure level for working and physical activity!
WBGT Flag Activity Intensity
< 80 F White Normal activity. Caution < 26.7 C should be taken.
80-84.9 F Green Discretion is required
26.7-29.4 C in planning intense
physical activity.
ctivity for new
29.4-31 C and unacclimatized persons should be curtailed.
88-89.9 F Red Intense exercise must 31-32.2 C be curtailed for those
with less than 12 weeks training in hot weather. Be on high alert
> 90 F Black Cancel all outdoor > 32.2 C exercise.
o
o
o
o
o
85-87.9 F Yellow Intense a
o
o
o
o
o
Source: Manual of Naval Preventive Medicine (NAVMED P-5010)
Work/rest regimen Light Moderate Heavy
(Each hour)
o o o
Continuous work 30 C 26.7 C 25 C
o o o
/86 F /80 F /77 F
o o o
75% work, 25% rest 30.6 C 28 C 25.9 C
o o o
/87 F /82 F /78 F
o o o
50% work, 50% rest 31.4 C 29.4 C 27.9 C
o o o
/89 F /85 F /82 F
o o o
25% work, 75% rest 32.2 C 31.1 C 30 C
o o o
/90 F /88 F /86 F
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Accuracy, the Zenith of Measuring / Testing Instruments !
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Data logger
Temp./RH transmitter
Wireless Transmitter ..........
3, Hagavish st. Israel 58817
Tel: 972 3 5595252, Fax: 972 3 5594529
mrc@mrclab.com
M
RC.7.17
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