testo 674X – Dew point transmitters
Product Description
testo 6741 – Dew point transmitter
• Dew point transmitter with a measuring range of -45 °Ctd to + 30 °Ctd and G½ thread
• Testo polymer humidity sensor with a high degree of accuracy and long-term stability
testo 6742 – Dew point transmitter
• Dew point transmitter with a measuring range of -45 °Ctd to + 30 °Ctd and NTP½ thread
• Testo polymer humidity sensor with a high degree of accuracy and long-term stability
testo 6743 – Dew point transmitter
• Dew point transmitter with a measuring range of -45 °Ctd to + 30 °Ctd, G½ thread and display
• Testo polymer humidity sensor with a high degree of accuracy and long-term stability
testo 6744 – Dew point transmitter
• Dew point transmitter with a measuring range of -45 °Ctd to + 30 °Ctd, NTP½ thread and display
• Testo polymer humidity sensor with a high degree of accuracy and long-term stability
Optimal for trace humidity measurement
The testo humidity sensor is generally calibrated at several points, resulting in minimal deviations. For trace humidity measurement, a calibration is also carried out at -40 °Ctd (dewpoint) with the aid of a high-precision reference measurement (dewpoint mirror) and logged. This provides the user with reliable and accurate readings in the relevant range (down to -60 °Ctd / -76 °Ftd).
Adsorption dryers
If chamber switching is humidity-controlled using Testo trace humidity transmitters rather than being time-controlled (see diagram on the right), the drying phases (blue) are usually much longer than the regeneration phases (red). During this time, no regeneration air needs to be generated, so the compressors can be switched back from 100 % to approx. 85 % volume flow. This results in significant savings in operating costs.
Refrigeration dryers and membrane dryers
Regardless of whether refrigeration or membrane dryers are used, without continuous monitoring of the dryer, damage is almost impossible to prevent. Blocked condensate drains and poorly closing bypass lines result in a measurable increase in humidity in the compressed air line.
