Data Sheet

ManualsBrandsDelta Ohm ManualsEnvironmental Testing EquipmentDelta Ohm HD32.3 PMV Kit Thermometer -40 up to +100 °C

HD32.3, HD32.3A, WBGT-PMV-PPD

HD32.3 instrument can detect simultaneously the following quantities:

• Globe thermometer temperature Tg with TP3276.2 (or TP3275) probe.

• Natural wet bulb temperature Tn with HP3201.2 (or HP3201) probe.

• Environment temperature T with TP3207.2 probe (or TP3207).

• Relative humidity RH and environment temperature T with HP3217.2 (or HP3217R)

probe.

• Air speed Va with AP3203.2 (or AP3203) probe.

Starting from the measured values, HD32.3 can calculate and display, with TP3207.2

(or TP3207), TP3276.2 (or TP3275), and HP3201.2 (or HP3201) probes, the following

indexes:

• WBGT (in) Index (Wet Bulb Glob Temperature: wet bulb temperature and globe

thermometer) in absence of solar radiation.

• WBGT (out) Index (Wet Bulb Glob Temperature: wet bulb temperature and globe

thermometer) in presence of solar radiation.

Starting from the measured values, the HD32.3 instrument can calculate and display,

with HP3217.2R (or HP3217R), TP3276.2 (or TP3276 or TP3275), and AP3203.2 (or

AP3203) probes, the following indexes:

• Medium radiant temperature TMR.

• PMV Index (Predicted Mean Vote).

• PPD Index (Predicted Percentage of Dissatisﬁ ed).

WBGT index

WBGT (Wet Bulb Globe Temperature – wet bulb and globe temperature) is one of the

indexes used to determinate the occupational heat exposure.

It represents the value, related to the metabolic expenditure linked to a speciﬁ c work

activity, that causes a thermal stress when exceeded.

WBGT index combines the measurement of wet bulb temperature t

with natural

ventilation with the globe thermometer temperature t

and, in some situations, with the

air temperature t

The calculation formula is the following:

• inside and outside the buildings in absence of solar radiation:

WBGT

close environments

= 0,7 t

+ 0,3 t

• outside the buildings in presence of solar radiation:

WBGT

outside environments

= 0,7 t

+ 0,2 t

+ 0,1 t

where:

= wet bulb temperature with natural ventilation;

= globe thermometer temperature;

= air temperature.

The measured data should be compared with the limit values prescribed by the

regulations;

when exceeded you have to:

• reduce directly the thermal stress on the examined work place;

• proceed to a detailed analysis of the thermal stress.

In order to measure the WBGT index, the following probes should be connected:

• Natural wet bulb HP3201.2 (or HP3201).

• TP3276.2 (or TP3275 or TP3276) Globe thermometer probe.

• TP3207.2 (or TP3207) Dry bulb temperature, of the measurement is performed in

presence of solar radiation.

In order to measure the WBGT index, you should refer to the following regulations:

• ISO 7726

• ISO 7243

• ISO 8996

PMV - PPD indexes

Human thermal comfort is deﬁ ned by ASHRAE (American Society of Heating, Refrigerating

and Air Conditioning Engineers INC) as the state of mind that expresses satisfaction with

the surrounding living or working environment.

The evaluation of this subjective condition can be objectiﬁ ed and quantiﬁ ed using

integrated index that consider the micro climatic environment parameters (Ta, Tr, Va, RH),

and the work-related energy metabolic expenditure MET, and the typology of clothing

(thermal insulation CLO) commonly used.

Among these indexes, the most precise one reﬂ ecting the inﬂ uence of the above

mentioned physical and physiological variables on thermal comfort is PMV (Predicted

Mean Vote).

Synthetically, it comes from the equation of the thermal balance whose result is compared

to a scale of psycho - physical health and expresses the average opinion (average

foreseen vote) about the thermal sensations of a group of subjects.

From PMV is derived a second index called PPD (Predicted Percentage of Dissatisﬁ ed)

that quantiﬁ es the percentage of subjects who will be dissatisﬁ ed with some micro

climatic conditions.

ISO 7730 regulations suggests PMV use in presence of following variables that inﬂ uence

the thermal balance:

• Metabolic expenditure = 1 ÷ 4 met

• Thermal resistance of clothing = 0 ÷ 2 clo

• Dry bulb temperature = 10 ÷ 30°C

• Medium radiant temperature = 10 ÷ 40°C

HD32.3 – WBGT - PMV Index is an instrument made by Delta OHM for:

• Analysis of hot environments using WBGT index (Wet Bulb Glob Temperature: wet bulb

temperature and Globe thermometer) in presence or absence of solar radiation.

• Analysis of the moderate warm environments using PMV index (Predicted Mean Vote)

and PPD index (Predicted Percentage of Dissatisﬁ ed).

Reference standards:

ISO 7243: Hot environments. Estimation of the heat stress on working man, based on

WBGT index (wet bulb globe Thermometer).

ISO 8996: Ergonomics of the thermal environment. Determination of metabolic rate.

ISO 7726: Ergonomics of the thermal environment – Instruments for measuring physical

quantities.

ISO 7730: Moderate thermal environments. Determination of PMV and PPD index and

speciﬁ cation of the condition for thermal comfort.

The instrument is provided with three inputs for probes with SICRAM module: the SICRAM

module is an interface between the instrument and connected sensor and communicates

the sensor parameters and calibration data to the instrument.

All SICRAM probes can be plugged into any of the inputs: they are automatically

recognized upon turning on the instrument.

The main features of the instrument are:

• Logging: data acquisition and logging in the internal instrument memory. Storage

capacity: 64 different logging sections, sample interval, user selectable.

• Start and stop can be set automatically with the auto-start function,

• Selectable measurement unit of the temperature: °C, °F, °K.

• The display of maximum, minimum, medium statistic parameters.

• The data transfer via RS232 or USB serial port.

HD 32.3, HD32.3A

INSTRUMENT FOR THE ANALYSIS OF THE INDICES:

WBGT - PMV - PPD

Summary of content (4 pages)

PAGE 1
HD32.3, HD32.3A, WBGT-PMV-PPD , HD32.3 instrument can detect simultaneously the following quantities: • Globe thermometer temperature Tg with TP3276.2 (or TP3275) probe. • Natural wet bulb temperature Tn with HP3201.2 (or HP3201) probe. • Environment temperature T with TP3207.2 probe (or TP3207). • Relative humidity RH and environment temperature T with HP3217.2 (or HP3217R) probe. • Air speed Va with AP3203.2 (or AP3203) probe. Starting from the measured values, HD32.
PAGE 2
• Air speed = 0 ÷ 1 m/sec • Water vapour pressure = 0 ÷ 2,7 kPa PMV is a particularly suitable index for the evaluation of work places with moderate microclimate such as houses, schools, offices, research laboratories, hospitals, and is useful to predict the number of people likely to feel uncomfortably warm or cool. According to ISO 7730 PMV values range between + 0,5 and - 0,5, provides comfort conditions corresponding to a percentage of dissatisfied (PPD) lower than 10%. (see table below).
PAGE 3
Average radiant temperature Tr The average radiant temperature is defined as the temperature of thermally uniform simulated environment that would exchange with a man the same thermal radiation power exchanged in the real environment. In order to evaluate the average radiant temperature, it is necessary to measure: the globe thermometer temperature, the air temperature, and the air speed measured close to the globe thermometer.
PAGE 4
Protection dimension: Resolution: Temperature drift @20°C: Drift after 1 year: Ø=80 mm 0.01 m/s 0.06% /°C 0.12 °C/years Connections Input for SICRAM module probes 3 Connectors 8 male poles DIN 45326 USB Interface Type Connection Baud rate USB 1.1 or 2.0 not isolated Mini-USB 460800 RS232C Serial interface: Pin: Type: Baud rate: Data bit: Parity: Stop Bit: Flow Control: Cable length: M12-8 poles. RS232C (EIA/TIA574) isolated from 1200 to 38400 baud.