Request a Quote

Name(Required)
This field is for validation purposes and should be left unchanged.

DSP-FCI | Portable Dewpoint Hygrometer

A fully self-contained, portable hygrometer designed to deliver precise trace moisture measurements of gases and dry compressed air for both industrial and laboratory applications.

With an accuracy of ±2 °C dewpoint and an overall range offered between -110 °C to +20 °C dewpoint, the Model DSP-FCI ensures reliable performance. The advanced dewSMART transmitter, utilizing ultra-high capacitance aluminum oxide sensing technology, guarantees unsurpassed repeatability and measurement precision — and is fully interchangeable without returning to Alpha Moisture Systems for calibration and setup. The hygrometer’s unique desiccant dry-down technology provides rapid response times, making it ready for spot-check readings with minimal air or gas usage. An integral sample flow control valve conditions high-pressure samples before introduction to the desiccant head assembly, and a built-in flow indicator with sample-specific gradation provides flow control.

Designed for ease of use, the DSP-FCI features a user-friendly interface and requires little to no maintenance. The digital screen offers versatile display options, allowing users to select from various moisture units, including °C, °F, ppb(v), ppm(v), ppm(w), g/m³, and lb/MMSCF. Additionally, the device includes a user-programmable parts per million (weight) function for specific gases, with pre-programmed settings for common gases like Air, Ar, H₂, SF₆, CO₂, and N₂.

Powered by six “C” type batteries, the DSP-FCI performs self-diagnostics on startup and includes an automatic switch-off function to conserve battery life, providing over 250 hours of continuous operation. The standard package comes ready to use with batteries installed, two meters of stainless-steel PTFE sampling hose, stainless-steel quick-connect fittings, a calibration certificate, an instruction manual, and an anti-static carrying case, ensuring you have everything required for immediate use.

Category:
Whatever the challenge — Alpha Moisture Systems has you covered.
  • Highly customised solutions
  • Trusted by industry leaders
  • Distributors worldwide
  • Over 30 years experience

Accurate and reliable dewpoint measurement

Key features

  • Unsurpassed sensitivity, speed of response, repeatability, stability and long service life
  • Dewpoint ranges offered between -110 °C to 20 °C, with accuracy of ±2 °C dewpoint
  • Integrated sample flow control valve preconditions high-pressure samples before introduction to the desiccant head assembly
  • Flow control provided by the built-in flow indicator with sample-specific gradation
  • Digital display shows engineering units in your selected measurement unit
  • Choose from various measurement units in °C or °F dewpoint and absolute values in ppb(v), ppm(v) ppm(w) g/m3 and lb/MMSCF
  • Six “C” type batteries offer more than 250 hours of use in continuous operation
  • Intuitive menu structure making it easy to use, view and set user preferences
  • Strong, durable and rugged construction

Technical Data

General
Sensor/Transmitter TypeSensor
User InterfaceEnglish
Factory CalibrationSupplied with a calibration certificate traceable to National and International Humidity standards
Accessories2m stainless steel braided PTFE hose, 1/4" NPT tapered fitting, female quick connector, pressure calculator, screwdriver
DocumentationInstruction manual, calibration certificate
Sensor
Sensing ElementUltra-high capacitance aluminium oxide
Dewpoint RangeDewpoint sensor overall range offered between -110 °C to +20 °C (-166 °F to +68 °F) dewpoint.
-110 °C to -20 °C (-166 °F to -4 °F) dewpoint
-100 °C to 0 °C (-148 °F to +32 °F) dewpoint
-80 °C to +20 °C (-112 °F to +68 °F) dewpoint
ApprovalsCE
Accuracy± 2 °C (±0.36 °F) dewpoint
Sensor CalibrationSupplied with a calibration certificate traceable to National and International Humidity standards
Repeatability± 0.1 °C dewpoint
Temperature CoefficientTemperature compensated for operating range
Sample Flow RateFlow independent, ideally 5 - 10 L/min.
Max 20 L/min
Response TimesDry to wet: -100 °C to -20 °C (-148 °F to -4 °F)
- Instantaneous; in less than 5 seconds
Wet to dry: 0 °C to -60 °C (14 °F to -76 °F)
- less than 120 seconds
Calibration Warranty12 months from date of dispatch
Electrical
Electromagnetic Compatibility (EMC)Immunity: Complies with EN 61000-6-1:2007
Emissions: Complies with EN61000-6-3:2007
Display2 x 20 character LCD with programmable contrast
Power Supply9V DC , six C type disposable batteries
Battery LifeExcess of 250 hours
ResolutionDisplay - 0.1 C dewpoint/0.1ppm
Repeatability± 0.1 °C dewpoint
Warm Up Time15 seconds
Engineering Units°C, °F, ppm(V), ppm(w), ppb(v) g/m³, lb/MMSCF
Fault ConditionsSelf diagnostics
Mechanical
Dimensions in mm (H x W x D)153 x 310 x 365
Weight5.8kg
Operating PressureAtmospheric to 0.5 barg
Operating Humidity (External)0-98% RH, non condensing
Operating Temperature-20 °C to +50 °C
Storage Temperature-20 °C to +50 °C Maximum 95% Non-Condensing
CableStainless steel braided PTFE sampling hose
Sensor Protection316 sintered stainless steel filter - 50 micron
FittingsSwagelok quick connect, 0.25" diameter compression tube fitting
Mechanical Warranty12 months in case of defective parts or faulty workmanship

Downloads

DSP-FCI User Manual (PDF)
DSP-FCI Datasheet (PDF)

What's in the box

DSP-FCI Portable Dewpoint Analizer
Model DSP-FCI Portable Dewpoint Hygrometer

Applications

AerospacePortable dewpoint meters are crucial in the production of aeronautical parts requiring vacuum furnace heat treatment with very dry argon, and for verifying the dryness of welding shield gas at the torch head according to NADCAP standards.
Breathing AirIn diving, firefighting, and defence applications, portable dewpoint meters are used to test high-pressure cylinder breathing apparatus to prevent equipment freeze caused by excess moisture, which could have fatal consequences.
Food and BeverageMoisture control is critical in the food and beverage industry to prevent food quality loss. Packaging foods in an atmosphere of dry gases like Nitrogen and carbon dioxide extends shelf life. Our AMT and AMT-Ex transmitters enable continuous trace moisture measurement, reducing waste and carbon footprint.
HDPE ProductionUtilised for spot-checking moisture in flammable gases like ethylene feedstock, portable dewpoint meters ensure safety and efficiency in the production of polyethylene to avoid decreased yields caused by excessive moisture.
Injection MouldingPortable dewpoint meters are used to verify the dryness of air circulating through plastic pellets, improving surface finish, colour, and opacity of products — increasing yields and reducing production costs.
Medical GasesEssential for ensuring the reliability and accuracy of moisture content in hospital air systems, portable dewpoint meters help conduct continuous monitoring and quarterly spot checks to prevent microbial growth and potential infection — meeting NHS HTM02 standards.
Natural Gas and LNGPortable dewpoint meters are vital for preventing freezing issues in pipelines and valves, and preserving gas calorific value by accurately measuring moisture during transit from extraction to storage.
Natural Gas TransferBy identifying moisture ingress in gas distribution networks, portable dewpoint meters ensure the reliability of domestic gas appliances by facilitating rapid problem identification and resolution.
PharmaceuticalsPortable dewpoint meters are crucial for spot checks on inert blanketing gases in medication and medical device production, preventing microbial growth and ensuring the dryness necessary for freeze-drying processes.
Power GenerationFor routine spot checks on hydrogen used in alternator cooling, portable dewpoint meters help maintain efficiency and safety by ensuring moisture is below critical levels to avoid condensation.
SF6 Circuit BreakersPortable dewpoint meters help avoid excess moisture — a potential cause of arcing which decomposes SF6 into corrosive products, taking the switch out of service and interrupting the power to the distribution network. 
Speciality GasesPortable dewpoint meters facilitate accurate moisture measurements in calibration gases, minimising the valuable product expended during the test process and ensuring compliance with specifications.

Frequently Asked QuestionsIf you have a question that’s not answered below, please contact us

Can you sample gas or air in hazardous areas/zones with the DSP-FCI?

No, we recommend using the DSP-Ex or SADPmini2-Ex portable hygrometers, which are certified intrinsically safe for use in hazardous areas. For full certification details, please refer to DSP-Ex and/or SADPmini2-Ex datasheets, available on their respective product pages.

Whatever the challenge,
you can rely on Alpha
Moisture Systems

If you require a customised trace moisture measurement solution, book a consultation with our expert technical team and find out how you can increase the efficiency and productivity of your operations.

Dewpoint Calculator for Trace Moisture Measurement

in Gases & Compressed Air