Why a whole moist-air series needs explicit pressure
8760 T/RH pairs do not uniquely determine a chart; pressure, source identity and invalid states belong together.
The source task was complete import
Ortemk asked to import 8760 temperature/RH values when a panel handled 3309 lines. A reply recommended a text file and the author confirmed success. Original numbers, pressure, units and image contents are unavailable; this is no reproduction or market-size claim.
Equal RH at different pressure is not the same state
Choose SI+C with Pa/kPa, or IP+F with psi and one finite positive constant pressure. RH is explicitly percent or fraction. Temperature domain is [-100,200] C/[-148,392] F; normalized RH is [0,1]. Raw vapour pressure must be below total pressure.
Raw RH/vapour pressure stay unchanged; PsychroLib humidity ratio is floored at 1e-7 and flagged bounded. RH 0 dewpoint/wetbulb use this bounded ratio, not exact dry-air zero. Saturation changes ice/water formula at 0.01 C/32.018 F; wetbulb changes at 0 C/32 F.
Humidity ratio is 0.621945×Pv/(P−Pv), so Pv must be strictly below P. Do not invent missing pressure; set SI/IP independently for every job.
| Setting | What to confirm |
|---|---|
| Pressure | Use the pressure for the complete series; changing it changes humidity ratio at the same temperature and RH. |
| RH scale | Choose percent or fraction; enter 80% as 80 for percent or 0.8 for fraction. |
| Unit system | Use Celsius with SI and Pa/kPa, or Fahrenheit with IP and psi. |
Complete records support the chart
Bind temperature and RH by explicit zero-based column index; optional time/ID index uses -1 for none. Preserve every header, original cell, CSV record ordinal and physical start/end line. No 3309-row prefix, inferred calendar/timezone, interpolation or silently dropped rows.
Return every row state, humidity ratio, dewpoint, wetbulb, enthalpy and specific volume. Invalid numbers/domains/physical pressure or unavailable/nonfinite derived states keep original identity and null derived fields. Whole-budget/root failure delivers no partial result.
Five complete downloads: rows CSV, JSON report, all-point SVG, exact original and settings. Downloads+full copied CSV+SVG preview≤64 MiB; full typed compact JSON≤32 MiB; aggregate≤96 MiB; binary+complete text/metadata UTF-8 census≤128 MiB. 512 MiB is a conservative preflight census, not measured maximum browser heap.
The screen previews 4000 Unicode scalars and at most 200 valid points; copied CSV and downloaded JSON/SVG stay complete. All valid points, including overlaps, remain; the report retains all 715 curve samples and invalid saturation regions. The complete task, from reading the source to displaying its result, has a 60-second deadline. Cancellation, failure or timeout clears the result and returns no partial output; keep the original and settings for a fresh run.
- Exact original determines identity; explicit settings determine derived meaning.
- Invalid rows and saturation regions remain explicit.
- Bound the screen; keep complete downloads and copied CSV.
References
- Ortemk — using all 8760 own hourly T/RH values
The author resolved the import problem using a text file. The discussion provides no original numerical values, pressure, units or time alignment, so it cannot serve as a numerical reference for your series.
- PsychroLib 2.5.0 — MIT, ASHRAE 2017 equations
PsychroLib supplies the moist-air equations under the MIT license. This tool retains the 1e-7 humidity-ratio floor and limits each root solve to 100 iterations.
Tools in this category
Expand a tool to see its steps, options and supported formats, then open its workspace.
Psychrometric series chartTurn a complete temperature/RH series into rowwise moist-air properties and an all-point chart, preserving original and invalid rows.
Bind CSV columns and units to calculate every moist-air row; keep original order and invalid records in complete outputs.
Steps
- Choose SI/IP,matching temperature/pressure units,the pressure value and RH unit.
- Bind zero-based T/RH columns and optional time/ID.
- Paste/select the wholeCSV;run and inspect complete row states.
- Download all five complete files;copy retains every CSV row.
Available options
- Unit system
- SI · IP
- Temperature unit
- °C (SI) · °F (IP)
- Pressure unit
- Pa (SI) · kPa (SI) · psi (IP)
- Constant pressure for the whole series
- 101325
Finite positive value; match the selected unit system.
- RH input unit
- Percent0–100 · Fraction0–1
- Temperature column (zero-based)
- 1
- RH column (zero-based)
- 2
- Time/ID column (-1 for none)
- 0
Capabilities and limits
- Paste or select one complete strictUTF-8 comma CSV with a header record:16 MiB,100,000 data records and 512 UTF-8 filename bytes. Choose one source. Clear pasted text before selecting a File; simultaneous File and text are rejected. One leading BOM remains in the exact original. Quoting, doubled quotes, embedded newlines and LF/CRLF/CR are accepted. Blank/ragged records remain invalid rows; malformed CSV, encoding or joint-budget failure rejects atomically.
- Bind temperature and RH by explicit zero-based column index; optional time/ID index uses-1 for none. Preserve every header, original cell, CSV record ordinal and physical start/end line. No 3309-row prefix, inferred calendar/timezone, interpolation or silently dropped rows.
- Choose SI+C with Pa/kPa, or IP+F with psi and one finite positive constant pressure. RH is explicitly percent or fraction. Temperature domain is[-100,200]C/[-148,392]F; normalized RH is[0,1]. Raw vapour pressure must be below total pressure.
- Return every row state, humidity ratio, dewpoint, wetbulb, enthalpy and specific volume. Invalid numbers/domains/physical pressure or unavailable/nonfinite derived states keep original identity and null derived fields. Whole-budget/root failure delivers no partial result.
- Raw RH/vapour pressure stay unchanged; PsychroLib humidity ratio is floored at 1 e-7 and flagged bounded. RH 0 dewpoint/wetbulb use this bounded ratio, not exact dry-air zero. Saturation changes ice/water formula at 0.01 C/32.018 F; wetbulb changes at 0 C/32 F.
- Joint ceilings:1,000,000 scalar solves,100 actual iterations per Newton/bisection root and 100,000,000 work units. CSV characters, original calls and actual iterations are charged. Refuse before iteration 101. Row/input/solve ceilings must also satisfy complete-output/memory preflight; simultaneous maximum axes are not promised.
- Five complete downloads:rows CSV,JSON report,all-point SVG,exact original and settings. Downloads+full copiedCSV+SVG preview≤64 MiB; full typed compactJSON≤32 MiB; aggregate≤96 MiB; binary+complete text/metadataUTF-8 census≤128 MiB.512 MiB is a conservative preflight census, not measured maximum browser heap.
- Screen previews 4000 Unicode scalars and at most 200 valid points; copiedCSV and downloadedJSON/SVG stay complete. All valid points including overlaps remain; all 715 curve samples and invalid saturation regions are reported. One absolute 60 s deadline covers native metadata/read,import,Worker,full validation,cleanup and first post-await UI publication. Cancel/failure/late messages publish no partial result.
- Browser-local; no content/filename upload. A full 8760-series and finite boundaries are measured in Node Worker; maximum joint capacity and browser acceptance are pending. No comfort classification, equipment design, per-row pressure model or Ladybug compatibility claim.