The SHX measuring head is an evolution of the tried and tested SH measuring head. It is able to operate in test conditions up to 125 °C thanks to the use of optical components, electronics and materials that are able to withstand high temperatures. Our development team tested a range of components over the SHX working range to achieve the best possible performance. By comparison with our state-of-the-art 373 reference hygrometer, we were able to verify that the performance meets or exceeds the specifications.
The key components of the SHX such as the optical module and fan assembly can be easily replaced by the user without the need for system re-calibration.
Sample Flow Control at High Temperature
Precise dew point measurement depends on controlled and stable gas flow over the dew point mirror and known pressure. Flow rate is especially critical at high temperature and humidity conditions. The SHX measuring head incorporates a sample fan with user controllable speed that maintains a stable flow within the recommended range of 0.3…1 liter per minute at atmospheric pressure. A high temperature motor is combined with a micro engineered aluminum impeller/cowl combination to maintain reliable and stable sample flow. Flow rate can be changed through the 473 front panel user interface or by serial commands.
Frost/Dew Point -30…+99 °C *
Relative humidity 5…99 %rh **
Temperature -50…+125 °C
Frost/Dew point ≤ ± 0.1 °C
Temperature ≤ ± 0.07 °C
Frost/Dew point ≤ ± 0.05 °C
Temperature ≤ ± 0.03 °C
* To measure -30 °C frost point, the SHX measuring head needs to be in a temperature environment below 10 °C. To measure dew points up to 99 °C the SHX measuring head must be at least 3 °C above the dew point temperature.
** Please note the operating conditions: The measuring head as well as the connectors must be operated under non-condensing conditions.
In combination with the T12 multichannel thermometer, the 473 is particularly well suited to climatic chamber validation projects.
The SHX measuring head is the very latest addition to the MBW range. It is based on some of the very latest high-performance technologies to achieve new levels of specifications and performance.
As a stable flow through a dew point mirror measuring head is essential to achieve stable measurement, we have focused much of the development on making sure that the SHX flow fan functions over the whole working range. It uses a high temperature motor and custom design fan together with digital control from the 473 base instrument. In the event of need, the flow module can be easily replaced without specialist knowledge.
In the event of damage to the SHX measuring head, it is possible to order a replacement that can be fitted by your local MBW representative or the user.