BL782 Precision Chilled Mirror Hygrometer (-30 to 75℃ dp)

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Accuracy ±0.10℃ DP

Range (-30 to +75) ℃ dp

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DescriptionFAQ?

Chilled mirror dew point meter is a precise technique for determining the water vapor content is gases by directly measuring dew point or frost temperatures. Using this technique a metal mirror is cooled until it reaches a temperature at which a thin layer of condensation begins to form on it. The dew layer is detected optically, and the mirror is held at that temperature. The mirror temperature, measures with a PRT, is an accurate indicator of dew or frost point.

FEATURES

Accuracy of ±0.10 °C
Measurement range -30℃ to +75℃
±0.01℃ sensitivity and fast response
Real time curve and data logging
With multi-points calibration
Dynamic contamination correction
Manual Forced frost function
Auto process the super cooled water

APPLICATION

Reference standard in calibration lab
Inlet air measurement for engine testing
Heating ventilation & air conditioning test
Environment monitoring in clean room
Wet control for metallurgical processes
Coating process monitoring in pharmacy
Reference humidity instruments for climatic and environmental chambers
Lithium Ion battery manufacture

SPECIFICATION

Dew point measurement range: (-40 to +90) ℃ dp
Dew point calibration range: (-25 to +70) ℃ dp
Dew point accuracy: ±0.10℃
Dew point resolution: 0.01℃
Dew point sensitivity: ±0.01℃
Dew point reproducibility: ±0.05℃
Response: Stable measure at +15°C dp within 1 minute
Temperature measurement range: -40℃ to +100℃
Temperature calibration range: -10℃ to +90℃
Temperature accuracy: ±0.05℃
Humidity range: 3.6...100%RH @23℃
Display units: ℃ dp, ℃, %RH, PPMv, L/min
Mirror material: Gold-plated copper
Mirror temperature sensor: Pt100, AAA (1/10 DIN)
Mirror Cooling: 3 Stage PELTIER
External Temperature sensor: Pt100, Class AA (1/3 DIN)
Cable material: Polyurethane with shielding layer
Sampling airflow pressure: < 1.5MPa
Display: 7 inch touch screen
Digital output: RS232
Analog output: Optional
Power supply:100-240VAC
Power consume: 12W
Ingress protection grade: IP54
Working condition: -20℃ to +50℃, < 95%RH
Dimension: W248mm x D240mm x H140mm
Weight: 3.5 kg

SCOPE OF DELIVERY

BL782 Chilled mirror hygrometer
Dew point sensor (M36 x 1.5 thread) with 2 meters cable
Ø3 x 115 mm Pt100 with 2 meters cable
Standard AC Power cord
Water-proof carrying case

OPTIONAL

ISO17025 accredited calibration certificate
Analog output 4-20mA

ORDERING MODEL #

BL782

What is the use of forced frost function?

Normally, the water vapor may be in the state of liquid or solid phase (dew or frost) if the temperature is below 0 ℃. The difference in the temperature at which the condensate layer stabilizes can be up to 3 ˚C, therefore the condensate phase must be known for correct calculation or validation of parameters such as relative humidity.

However, it is also possible that dew and frost can exist concurrently on the mirror; this results in a non-stable value somewhere between the dew and frost point.

Force frost function overcools the mirror to force the condensed layer to the solid phase. This eliminates the uncertainty of whether dew or frost point is measured.

After this function is enabled, the device will automatically trigger the forced frosting if the following conditions are met:

A. -35℃<DP<-3℃;

B. The sensor is in stable control state for 30 seconds;

C. Frost thickness is from 80% to 120%, and stable for 30 seconds.

How to caculate the relative humidity ?

**Appendix 1: Dew Point – Humidity Conversion**

This appendix provides the formula and results for converting between dew point of moisture in gas and µL/L (PPMv).

The conversion from dew point to µL/L (PPMv) is calculated using the following formula:

计算公式1.png …………………………(1)