Dew point online monitoring system - SKA/WSD-LDY

Dew Point Meter Online Monitoring System

Dew Point Transmitter

1:SKA/WSD-LDYThe SKA/WSD-LDY dew point transmitter uses a polymer high-molecular sensitive capacitor, with fast response, stable and reliable, measuring range-80°C~20°CTdAccuracy: ±2°CTdThis product has automatic zero-point calibration and automatically heats to clean chemical substances attached to the sensor surface, ensuring extremely stable long-term use. This polymer dew point capacitor is the result of over 20 years of arduous research. Typically, polymer capacitors struggle to measure below-40°CTdDew point, due to the low rate of change, the signal is difficult to distinguish in the circuit. We conducted extensive fundamental research and finally mastered the technology to improve low-humidity sensitivity. Currently, from-70°CTdChange to-50°CTdUnder conditions, the base capacitance changes from300pFChange to305pFExceeding all polymer dew point capacitors on the market.

Dew Point Meter Online Monitoring System

2: Output signal:

Analog:4‑20mA Two-wire system (most common in industry, loop-powered)

Digital:RS485 Modbus‑RTUCan simultaneously output dew point and temperature; some models can outputPPMV Moisture concentration.

Common thread interfaces:G1/2、NPT1/4Screw directly onto the pipeline; the probe has a sintered filter to protect the sensor and block dust particles.

3. Typical application scenarios

Compressed air systems: Online monitoring at the outlet of refrigerated dryers and adsorption dryers to determine whether the dryer has failed, meeting ISO8573 Compressed air quality standards.

Industrial gases: Nitrogen, argon, hydrogen,SF6 Insulating gas, high-purity gas, glove box.

Plastics industry: Monitoring hopper drying gas to prevent product bubbles and silver streak defects.

Pharmaceutical, lithium battery, semiconductor: Clean gases, freeze-drying equipment, inert protective gases.

Power:GISTransformer insulationSF6 Trace moisture monitoring in gas.

Dew Point Meter Online Monitoring System

4. Key selection parameters

Dew point range

Refrigerated dryer: Generally 0 ~ ‑20℃Td

Adsorption dryer:‑40 ~ ‑70℃Td

Ultra-dry high-purity gases:‑80 ~ ‑100℃Td

Try to keep the actual operating dew point in the middle of the range; do not use at the range limits for extended periods.

Accuracy: General industrial ±2℃TdHigh precision ±1℃Td within. Low dew point (-60Accuracy degrades below ℃).

Pressure resistance: Confirm the pipeline working pressure; compressed air is generally 0.7‑1.0MPaFor high-pressure conditions, choose a high-pressure type.

Medium operating conditions: Check whether the gas contains oil mist, dust, or solvent vapor; for heavy oil vapor conditions, install a pre-filter for sampling.

Output method: Two-wire 4‑20mA OrRS485Power supplyDC12‑24V。

Calibration cycle: General 1‑2 Requires annual laboratory calibration; the sensor will drift slowly.

Dew Point Meter Online Monitoring System

5. Installation and usage points

Install downstream of the dryer and upstream of the point of use, avoiding elbows, dead corners, and water accumulation areas; install the probe vertically or facing downward.

The dew point transmitter measures pressure dew point; when atmospheric dew point is needed, pressure conversion is required.

Liquid water must not directly hit the sensor, as it can cause damage; if there is condensation risk, choose an anti-condensation sensor.

Gas flow rate should not be too high; for high-pressure and high-flow conditions, a sampling pressure-reducing circuit is recommended.

Oil vapor can contaminate aluminum oxide sensors; oil removal filters must be installed.