indoor air quality: Hand Held digital Instruments for temperature , Humidity & dew point Measurement

A variety of hand held digital hygrometers ranging in sophistication from the Lufft (E)conomy series to the Dostmann P670 with RS232 communications port.

Units measured are temperature, Relative humidity, Absolute humidity, dew point & wet bulb temperature.

We look forward to hearing from you soon to discuss your requirements or maybe a product brochure request. Please either phone (01767 692692), email, or use the  Contact us page to get in touch. Thank you.

Dostmann P670 For the measurement of relative humidity (rH) & temperature. Other functions such as dew point measurement & calculation of absolute humidity are possible, making the P670 suitable for use in air-conditioning & environmental engineering, biology and laboratory applications. Logger version available. Measuring range humidity: 0%rH - 100%rH temperature: -30°C - +140°C Combination probe for humidity & temperature weight: 300g Power supply: 9v Battery (Optional a/c power supply available) RS232 Port
Lufft C200 Mid priced  Thermo-Hygrometer for climate monitoring in buildings,control cabinets, store rooms & museums. Measuring range : 0-98% rH                                                                                                        -20...+50C.                                      Hold/Max/Min/Avg/Date/Time/Auto-Off. Dewpoint/Absolute/Relative.    Lufft C210 as above with cable mounted probe.
Dostmann H560 DewPoint Pro Sturdy industrial instrument for indoor climate monitoring. Max-Min-Hold Disable Auto-Off Dew Point Temperature Wet Bulb Temperature
Lufft E200 Economy Series Digital Thermo-Hygrometer   Hold/Max/Min/Average Single Point Calibration Dew Point Calculation One hand operation
Lufft E200 IR Economy Series Thermo-Hygrometer + IR Pyrometer Hold/Max/Min/Average Single Point Calibration INFRARED- Mode for non-contact surface temperature measurement DP-Mode- dew point & surface temperature displayed Alarm One hand operation
Chino HN-CH palm sized humidity logger (8000 data sets) with field replaceable sensors.

We look forward to hearing from you soon to discuss your requirements or maybe a product brochure request. Please either phone (01767 692692), email, or use the  Contact us page to get in touch. Thank you.

Glossary of terms:

Humidity Measurement

Relative Humidity; Unit:%

By relative humidity we refer to the ratio of water vapour actually present in the air to the maximum possible mass of water vapour in the air.

Since the maximum humidity is dependent on temperature, relative humidity changes with temperature, even when the absolute humidity remains  constant.

Absolute Humidity; Unit:g/M3

By absolute humidity we refer to the volume of water vapour actually present in a specific quantity of air. Absolute humidity is the ratio of the weight of the water contained in the air and the volume of this moist air.

Water Vapour Partial Pressure

Saturation Vapour Pressure

Unit: hPa

By saturation vapour pressure eS(T) we refer to the maximum possible pressure of the water vapour at a certain temperature. The water vapour partial pressure e(t) varies between 0 (dry air) and 30hPa. The saturation vapour pressure determines the upper limit.

Saturation  humidity, maximum humidity, saturation quantity

Unit:g/m3

By maximum humidity hmax, we refer to the maximum possible water vapour quantity in a cubic meter of air at a certain temperature . The moisture absorption capacity of air increases with increasing temperature. If the maximum humidity is exceeded, the excess water vapour condenses in the form of condensate (droplet formation).

Dew-Point

Unit: °C, °F, °K

By dew-point temperature Td, we refer to the temperature at winch the cooling of moist air leads to condensate formulation. This means that when moist air is cooled down to dew-point, the relative humidity rises to 100%.

Frost point

Unit: °C, °F, °K

In some cases where dew-point temperatures are below 0°C, we refer to the frost point temperature. Other descriptions are also dew-point temperature above ice or freezing point.

Specific Enthalpy (heat content)

Unit: kJ/kg

By specific enthalpy Espez, we refer to the quantity of heat necessary to raise the temperature of a gas (or gas mixture) from one temperature to another at a constant pressure.

Or;

By specific enthalpy we refer to the quantity of heat that is available in the air mass relative to a certain air condition. The enthalpy of unsaturated air is the sum of the  enthalpy to vaporise the water content present, plus enthalpy to heat the water vapour mixture to the corresponding temperature.

Mixing Ratio

Unit: g/Kg

By mixing ratio m, we refer to the ratio of water vapour mass to the mass of dry air.

Wet Bulb Temperature

Unit:°C, °F, °K

By wet bulb temperature WBT in psychrometric measurement, we refer to the temperature output or indicated by a thermometer probe wrapped in a moist wick.