Humidity Generator
- General description
- Technical data
Humidity Generator (GVG) mod. GVG-901, GVG-902
Humidity Generator modifications GVG-901, GVG-902 are used for reproduction of set values of relative humidity and the dew point in vapor-gas mixtures. They can be used for calibration and verification of gas analyzers after production or repair, during the operation period or after a long-term storage.
According to the GOST 8.547-2009 generators are qualified as:
– 1st grade working standard for reproduction of relative humidity in a vapor-gas mixture (for modifications GVG-901 and GVG-902)
– 2nd grade working standard for reproduction of dew point of a vapor-gas mixture (for modification GVG-902)
Construction and basic modifications
GVG Generator is a stationary one-block device that consists of gas system and a control block. The generator has two gas flow channels: the first one is for a dry diluting gas; the second is for humidified gas. The generator has also an output line for sampling of the prepared gas mixture. The generator is produced in two base modifications: GVG-901 and GVG-902. Modification GVG-902 has an additional option for reproduction of dew point in humidified gas.
Operating Principle
Humidity Generator GVG modifications GVG-901, GVG-902 (later – generators) are based on the principle of mixing humidified and dry diluting gas flows. Their flow rate is regulated and measured using mass flow controllers. The required values of flow rates in the channels in a produced vapor-gas mixture are to be calculated. Humidification of the flow is performed by bubbling through water.
The simulated values of the relative humidity and the dew point are determined by inbuilt highly accurate relative humidity sensors (for modifications GVG-901, GVG-902) and dew point sensors (for modification GVG-902). Values of the relative humidity and the dew point determined by sensors are displayed on the LCD, located at the front panel of the generator.
Advatages
– High precision due to individual calibration of flow rate channels and usage of the precise built-in sensors of relative humidity and temperature of a dew point .
– Wide range of reproduction of gas humidity.
– Possibility to work in manual, autonomous (generator calculates the required operation modes based on the initial set parameters) and automatic (from PC) modes.
– Long exploitation period.
TECHNICAL CHARACTERISTICS
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Humidified gases |
Air, Nitrogen, Methane, Argon, Helium |
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Range of gas relative humidity |
from 0 to 98 %* |
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Limits of permissible absolute error by the channel of relative humidity |
±1.0 % |
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Limits of permissible absolute error of temperature measuring in the chamber of relative humidity of the generator |
± 0.2 °С |
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Range of dew point temperature (for GVG-902) |
from – 80 to + 20 °С ** |
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Limits of permissible absolute error for the channel of dew point temperature (for GVG-902) |
±1.0 °С |
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Range of settings and measuring volume flow of the prepared gas mixture at the outlet of the generator |
from 0.1 to 5.0 l / min |
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Setting time of the target value of relative humidity of gas mixture at the outlet of the generator |
60 min |
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Setting time of the target value of dew point temperature (DPT) of vapor-gas mixture at the outlet of generator GVG-902 |
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DPT up to 60 °С |
up to 60 min |
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DPT from 60 to 80 °С |
up to 180 min |
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Warm-up time |
up to 60 min |
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Power supply from AC |
220 V, 50 Hz |
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Dimensions, (LxWxH): |
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generator GVG-901 |
515 х 410 х 330 mm |
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generator GVG-902 |
515 х 485 х 330 mm |
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Weight |
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generator GVG-901 |
20 kg |
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generator GVG-902 |
27 kg |
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Average lifetime |
not less 8 years |
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Operating Conditions |
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Ambient temperature |
from 15 to 25 °C |
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Relative humidity |
to 98% at 25 ° C |
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Atmospheric pressure |
from 84.0 to 106.7 kPa |
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*In order to reach 0% relative humidity, generator has to be used in manual mode using only dry gas channel. In order to reach 98% relative humidity, generator has to be used in manual mode using only humid gas channel.
**When the generator is used in autonomous mode or automatic mode (from PC), the minimum dew point temperature is -80 C° in the case of using of special pure nitrogen as an initial gas (or any other working gas) with the dew point temperature -90 C° (at atmospheric pressure).