Estimate dew point pressure with reliable engineering inputs. Review trends, compare scenarios, and export results. Designed for process teams needing quick accurate moisture decisions.
Engineering note: dew point pressure equals vapor partial pressure for current air composition at the condensation threshold.
| Case | Dry Temp (°C) | RH (%) | Total Pressure (kPa) | Estimated Dew Point (°C) | Dew Point Pressure (kPa) |
|---|---|---|---|---|---|
| Dry Room Air | 25 | 40 | 101.325 | 10.45 | 1.268 |
| Humid Line | 32 | 75 | 101.325 | 27.10 | 3.564 |
| Compressed Air Dryer Check | 20 | 20 | 700 | -3.65 | 0.468 |
| Steam Adjacent Space | 38 | 85 | 101.325 | 35.10 | 5.636 |
Values are representative examples for planning and validation. Calibrate field instruments before operational decisions.
1) Saturation pressure at dry-bulb temperature:
es(T) = 0.61094 × exp[(17.625 × T) / (T + 243.04)] (kPa, T in °C)
2) Actual vapor partial pressure:
pv = (RH / 100) × es(T)
3) Dew point temperature (Magnus inversion):
γ = ln(RH/100) + (17.625 × T)/(243.04 + T)
Td = (243.04 × γ) / (17.625 − γ)
4) Dew point pressure: pdew = es(Td) = pv
This implementation is suited for common engineering humidity calculations near standard ranges. Extreme temperatures may need a different correlation.
Dew point pressure is a practical indicator for condensation risk in air, gas, and process lines. Engineers use it to verify dryer performance, protect instruments, and reduce corrosion exposure. A higher dew point pressure means more water vapor in the mixture, even when total system pressure changes. In compressed air systems, tracking this value supports maintenance planning, startup validation, and reliable moisture control decisions across production areas.
Temperature and relative humidity drive dew point pressure estimates. Warm air holds more vapor, so equal humidity percentages at higher temperatures usually produce higher vapor partial pressure. For example, air at thirty degrees and sixty percent humidity contains more moisture than air at twenty degrees and the same humidity. Technicians should log both readings together and confirm sensor calibration dates because small humidity errors can shift calculated dew point values.
Dew point pressure equals water vapor partial pressure at the condensation threshold, but total pressure still helps engineers interpret process behavior. The calculator reports water vapor mole fraction using total pressure, which supports comparisons between atmospheric air and pressurized gas lines. In compressed systems, expansion and cooling can change condensation risk quickly. Reviewing mole fraction with dew point pressure gives clearer insight for dryers, regulators, and downstream instrument protection.
Operating conditions change with weather, load, and equipment cycles. A safety margin on dew point pressure adds conservatism for alarms, dryer settings, and inspection thresholds. Teams often apply margins when sensors are distant from critical points or process conditions fluctuate rapidly. Margin adjusted values do not replace laboratory verification, but they improve field decisions. Comparing baseline and margin results in exports also supports maintenance reviews and recurring performance checks.
CSV and PDF exports make calculator outputs useful for commissioning, troubleshooting, and audits. Engineers can attach result snapshots to work orders, quality records, and preventive maintenance reports. A consistent result set including dew point temperature, dew point pressure, vapor pressure, and tolerance range improves communication across operations and QA teams. Archived exports create a practical moisture history, helping identify trends before condensation causes reliability or product quality issues. Documented Documented Documented Documented Documented Documented Documented Documented Documented Documented Documented Documented Documented Documented Documented Documented Documented.
Dew point pressure is the vapor partial pressure where moisture starts condensing. It indicates the actual moisture threshold for the measured air or gas sample.
Both values are needed because humidity percentage depends on temperature. Changing temperature changes saturation pressure, which directly changes dew point and vapor pressure results.
Total pressure helps estimate water vapor mole fraction for engineering interpretation. This is useful when comparing atmospheric readings with compressed process systems.
It increases the calculated dew point pressure by your selected percentage. Use it for conservative thresholds, alarm points, and dryer setting decisions.
Sensor tolerance adjusts relative humidity upward and downward, then shows a dew point range. This highlights uncertainty caused by field instrument accuracy limits.
Export results for commissioning records, maintenance logs, audits, and troubleshooting. Saved outputs improve traceability and support comparisons across operating conditions.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.