A cold mirror dew point meter developed and tested in collaboration with the National Physical Laboratory (NPL) of the United Kingdom,

It can measure very low dew point temperatures as low as -100 ° C. Stage 1- Challenge: The cold mirror dew point meter is calibrated for measuring micro water and humidity

Important reference instruments. It directly measures the formation of condensation on the mirror surface. Ensuring that the formation of condensate is repeated as much as possible is the basis for measurement.

Without external cooling, the current drying parameter of the cold mirror dew point meter is 90 ° C frost point, which is equivalent to approximately 95 ppb.

The challenge lies in expanding the measurement capability to -100 ° C frost point, or approximately 14 ppb. There are also cold mirror dew point meters that can achieve external cooling

This ability, but with a large volume. Expand the internal cooling lower limit range of the cold mirror dew point meter to enable countries and other certifications around the world

The low range measurement in the laboratory is limited to frost points over -90 ° C, which helps this field to achieve repeatability within the dew point/frost point range

The next step in reproducible measurement is taken. Without external cooling, the cold mirror dew point meter can be fully cooled,

To obtain a stable condensation layer at -100 ° C. What our engineers need to further explore is: • Condensation formation and measurement head design

The relationship between the flow dynamics brought about by the Stirling engine and the flow path between the mirror and the material properties of the cold interface condensation layer

The temperature measurement at the point where the water in the flow path is in equilibrium is crucial. Engineers know they need to look at PRT

(Platinum resistance thermometer) for this measurement, and what improvements can be made to it and its installation. Solving this problem from before

During the experiment, engineers learned that current devices can measure as low as the required level. In fact, NPL has previously been at -100 ° Cdp

Calibrating a device has highlighted some repetitive issues that need to be addressed. There is a strong correlation between the measured values and the sample gas flow rate.

Despite the challenges, it is crucial to address the issue of expanding the parameters of the cold mirror drying end. This not only enables them to extend UKAS certification

To a frost point level as low as -100 ° C, and will directly benefit customers by improving the dry end performance of its calibration instruments.

Phase 2- Prototype As a phase, we developed a prototype cold mirror dew point meter based on the previous design, but with upgraded measurements

Head and airflow path to ensure the formation of condensate is as reproducible as possible. The testing conducted at NPL contributes to the evolution of the design.

The dry end specification parameters of the prototype cold mirror are at a frost point of -100 ° C (approximately 14 ppb). By utilizing the available cooling capacity, they may be able to

-A stable condensation layer is formed at 100 ° C. Although we are testing the prototype at the Yili factory, we hope for NPL humidity measurement and standards

Participate in the group. NPL's expertise provides the final information needed to update the design of measurement heads. Through the participation of NPL and their

The use of facilities, knowledge, and equipment enables our R&D personnel to validate designs without the need for third-party beta testing. just as

As explained by product manager Richard Gee, 'We don't believe we can carry out the necessary work in a timely manner, so let's reconsider.'

Design with confidence to launch the product in the current iteration. With the help of NPL, we have shortened the time to market by at least three months

Why is precise measurement of low dew point important? Cold mirror dew point meters are used as many instruments and sensors in commercial laboratories

Reference for calibration of trace moisture and dew point (such as dew point transmitter). Improving the dry end specifications of this reference will ensure the calibration of these instruments

High reliability within a lower measurement range. How does a cold mirror sensor work? A cold mirror dew point meter is used for critical measurement and control applications

Precision instruments. One of the main characteristics of a cold mirror sensor for measuring moisture is the temperature at which condensation forms on the mirror surface. This means a cold mirror

The instrument has inherent repeatability and can provide reliable results every time. The cold mirror sensor consists of a temperature controlled mirror and an optical detection system

The gas sample enters the sensor housing and flows through the included cold mirror surface. Depending on the moisture content in the gas and the working pressure

At a certain temperature, moisture in the gas condenses on the mirror surface. The optical system is used to detect the point where this situation occurs, and this information is used for

Control the temperature of the mirror surface and maintain a constant thickness of the condensation layer on the mirror surface. At the equilibrium point, where the evaporation rate and condensation rate of the mirror surface are equal,

The mirror temperature represents the dew point.