Microtherm Heat Stress monitor.Workers exposed to hot working environments can be susceptible to heat stress
Workers exposed to hot working environments can be susceptible to heat stress, when the core body temperature rises to dangerous or hazardous levels. This can result in physiological symptoms like heat cramps, nausea, palpitations, stroke and possibly death. An overall estimation of the heat stress levels on a body can be measured using the Wet Bulb Globe Temperature (WBGT) Index. This combines the results from three temperature sensors into a single calculated value that may be compared with reference values depending upon the specific work regime. The WBGT meter measures simultaneously from three PRTD sensors for wet bulb (tnw), dry bulb (ta) and globe (tg) temperatures. Sensors are manufactured to high accuracy standards: BS 1904 and DIN 43760. The sensors can be mounted directly onto the body of the instrument or they can be remotely positioned via a 30 ft cable. Both meter and sensor unit have a tripod socket for ease of use. WBGT values are calculated simultaneously according to the following formulae for indoors and outdoors. WBGT(in) = 0.7tnw + 0.3tg or WBGT(out) = 0.7tnw + 0.2tg + 0.1ta Processed data values include: WBGT(indoors), WBGT(outdoors), 1 hour (TWA) WBGT values, Relative humidity (%), Dewpoint temperature.
Logged values include date and time plus all measured and computed values. Data Logging intervals from 30 seconds to 1 hour. Results are stored in either °F or °.C.
Features
Large LCD screen; Real time display of changing levels; Data-logging as standard
Low water level alarm; Audible & visual warning of level excedances
RH% and dewpoint calculation
Windows PC software for setup and download of results from memory
Automatic calculation of work/rest regimes with included PC software
Tripod mounting for extended surveys
Meets the requirements of ISO 7243
Applications
Construction / Power stations / Foundries / Steel works / Bakeries / Glass manufacturing / Routine monitoring / Medical surveillance testing
SPECIFICATIONS
Measurement
Sensing technique
Platinum resistance temperature detectors (PRTD) 100 elements 0.1% using 4 wire cable up to 30 ft (10m)
4 x AA MN1500 cells, Alkaline or rechargeable NiCad
Battery life
20 hours NiCad cells or 85 hours Alkaline cells
External supply
100 - 240 VAC Universal transformer with intelligent internal NiCad fast charger circuitry
Physical
Display
128 x 64 pixel LCD graphics screen with backlight
Keypad
7 key tactile membrane
Weight
26.5 oz (750 gm) instrument only
Dimensions
10.0 x 3.7 x 2.0 in (245 x 95 50 mm)
Displayed and stored values
Wet Bulb Globe Temperature Indoors & Outdoors Wet Bulb Globe Temperature Indoors & Outdoors TWA Ta, dry bulb, air; Tg, globe; Tnw, natural wet; Dewpoint Relative humidity %
Additional stored values
WBGT Indoor & Outdoor max, min and average values WBGT Indoor & Outdoor TWA maximum, minimum values Ta, dry bulb, air maximum, minimum and average values Tg, globe maximum, minimum values Tnw, natural wet maximum, minimum and average values
