Dew Point Meter (Portable / Online)
Electrolytic measurement of dew point or trace moisture in non-corrosive and acid gases, 10 ppb precision, -80 to -6 °C Td, acid-gas capable, with over 12 hours of handheld battery life.
Purpose | What it does for you
The portable DPM-16H is for field rounds and the online DPM-16L for continuous monitoring, measuring dew point or trace moisture in non-corrosive and acid gases. Trace water in gas causes catalyst poisoning, product defects, pipeline corrosion and ice blockages, and 10 ppb capability makes it suitable for high-purity gases, petrochemicals, power-industry SF6, lithium battery dry rooms and pharmaceutical process gases.
Key Features
- 10 ppb precision, dew point -80 to -6 °C Td (online model -90 to -6 °C Td)
- Corrosion resistant: measures acid and mildly corrosive gases
- Portable: high-performance rechargeable battery, over 12 hours continuous operation per charge
- Direct measurement on connection, no bypass flushing; sensor over-range protection
- Online model: ExdIIBT4 explosion-proof, IP65, RS485 networking, remote monitoring over 100 m
- Online model includes a gasification chamber for liquefied gas and constant-temperature operation
Operating Principle
A coiled double platinum wire with a gap of less than 20 µm forms an electrolytic cell. Phosphorus pentoxide in the gap absorbs trace water to form phosphoric acid, generating a small current proportional to the amount of water absorbed; dew point or trace water content is calculated from the measured current. This electrolytic method is absolute, highly accurate and works with acid and mildly corrosive gases.
Technical Specifications
| Dew Point Range | -80 ℃Td ~ -6 ℃Td (online -90 ~ -6 ℃Td) |
|---|---|
| Repeatability | ≤±1 ℃Td |
| Water Content Range | 0.5 ppmv ~ 3800 ppmv (online 0.1 ~ 3800 ppmv) |
| Measurement Error | 0.5 ppmv or 1% m.v. (online 0.1 ppmv or 1% m.v.) |
| Flow Rate | 100 sccm (adjustable online) |
| Response Time | <5 min |
| Battery | 4 h charge, 12 h operation |
| Gas Supply Pressure | 0.1 MPa (online ≤1 MPa) |
| Dimensions | 230 × 90 × 142 mm (online 300 × 120 × 360 mm) |
| Operating Environment | -10~45 ℃ (online -30~50 ℃) |
| Explosion-proof Class | ExdIIBT4 (online model) |
| Interface Size | 1/8 in metal tube |
| Power Supply | Built-in battery / USB (online AC 220/110 V or DC 24 V) |
Note: Due to continuous product iteration and varying application conditions, the technical parameters on this page are typical reference values and are not to be used as acceptance criteria. For tender and customized projects, the product model, configuration and specifications are subject to the mutually confirmed technical agreement and the actual delivered product. For parameter matching tailored to your specific project, please contact us.
Standard Configuration
Instrument, charger/power supply, sampling tube (1/8 in metal fitting), carrying case, manual and factory calibration certificate. The online model also includes RS485 communication and monitoring software. Final scope per the configuration list.
Application Scenarios
- Moisture release testing in high-purity gas production (N₂, Ar, H₂, O₂)
- Trace moisture monitoring of SF6 electrical equipment (GIS, circuit breakers)
- Dew point rounds in lithium battery dry rooms and glove boxes
- Moisture monitoring in petrochemical and natural gas processing (ice blockage and corrosion control)
- Moisture verification of pharmaceutical process gases and sterile compressed air
Compliance Standards
Industries Served
- Petrochemical & Energy
- Pharmaceutical & Biopharmaceutical
- Food & Condiments
- Material R&D, Universities & Institutes
- Third-Party & Government Testing Institutes
- Public Health CDC & Customs Technical Centers
- Environmental Monitoring & Solid Waste
- Building Materials & Construction
Frequently Asked Questions
Can it measure acid gases? Will the sensor be damaged?
Yes. The electrolytic sensor is inherently corrosion resistant and handles acid and mildly corrosive gases. It also has over-range protection that triggers when moisture exceeds the range, avoiding sensor damage. For strongly corrosive gases or gas containing particles or oil, a pre-treatment unit is still recommended.
How do I choose between portable and online?
Choose the handheld DPM-16H for multi-point rounds, spot checks or mobile use (12+ hours per charge). Choose the online DPM-16L for continuous monitoring, DCS/SCADA integration or hazardous areas (ExdIIBT4, IP65, RS485). Both share the same measuring principle, so data are comparable.
Does LabStone support OEM/ODM and customised instruments?
Yes. Standard models ship as-is, while chamber count, specimen size, fixtures, temperature range and software modules (including the GMP Computerized System module) can be tailored to your SOP and URS. IQ/OQ/PQ validation documentation packages are available.
What is the typical lead time, and how is shipping handled?
Standard models usually ship in 4–8 weeks; customised builds depend on the agreed scope. Instruments are packed in export wooden cases and can move by sea, air or rail. We supply proforma invoice, packing list and certificate of origin (CO / Form E), and work under EXW, FOB, CIF or DAP terms.
How are installation, training and calibration handled after delivery?
We provide remote installation guidance, bilingual (Chinese/English) manuals and video training; on-site commissioning by our engineers is available. Users can self-calibrate with standard weights, reference films or calibrated leak standards, and third-party calibration certificates can be supplied.
What is the warranty, and how are spare parts supplied?
The instrument carries a 12-month warranty from acceptance plus lifetime maintenance support. Consumables (molecular sieve, desiccant, sealing grease, printer paper) are kept in long-term stock, and key components are international brands available worldwide. We respond to technical enquiries within 24 hours.
Do the instruments comply with ASTM, ISO and pharmacopoeia standards?
Yes. Every instrument lists its applicable standards on the specification page (ASTM, ISO, GB, YBB, Chinese Pharmacopoeia, USP, EP, JIS, DIN, TAPPI and more). The software outputs raw records and reports suitable for audit trails, with an optional GMP / FDA 21 CFR Part 11 compliance module.
Which languages does the software support, and can it integrate with a LIMS?
The software ships with Chinese and English interfaces; other languages can be added on request. Data export is available over RS232, USB, Ethernet or Wi-Fi, and reports can be exported to Excel, PDF or structured files for LIMS integration.