Instrument Selection Calculators
These tools answer a question that product catalogues do not: given what you are measuring, what range and accuracy do you actually need? They convert a process description into a specification you can send to a supplier — and into a shortlist of instrument families that meet it. Each one states its assumptions and its limits, because a calculator that hides its error band is worse than no calculator.
Range and accuracy selection
pH & ORP Range Calculator
Enter your water type and installation, get the measuring range, resolution, accuracy class, electrode type, buffer set and panel cut-out to specify.
Open the calculator →Unit conversion and interpretation
Conductivity to TDS Calculator
Convert EC in µS/cm to TDS in mg/L, and see which conversion factor belongs to drinking water, brine, hydroponics and industrial process.
Open the calculator →Turbidity to TSS Converter
Estimate suspended solids from a turbidity reading, with benchmark correlations by water type and a method for deriving your own site-specific factor.
Open the calculator →Dissolved Oxygen Saturation Calculator
Get the saturation ceiling for your water temperature and altitude, then read your instrument against it as percent saturation — the number that tracks biological demand.
Open the calculator →COD Dilution Calculator
Work from your own calibration curve: absorbance gives concentration, and the tool tells you whether your reading sits in the reliable band or needs further dilution.
Open the calculator →What these tools assume
| Tool | Assumes | Does not do |
|---|---|---|
| pH & ORP Range | Fresh, unbuffered samples at ambient temperature | Cannot predict fouling rate or select a wetted material without chemistry data |
| Conductivity to TDS | A single conversion factor fits the dissolved species | Cannot replace a gravimetric TDS determination for reporting |
| Turbidity to TSS | Particle size and refractive index are constant | Cannot be used for permit reporting; turbidity and TSS are different measurements |
| DO Saturation | Freshwater, 1 atm reference, altitude-adjusted | Does not correct for salinity; high-altitude error reaches about 2% above 2000 m |
| COD Dilution | Your calibration curve is current and linear | Cannot replace EPA 410.4 or SM 5220 B for a reported value |
Instruments these tools point to
Benchtop pH, lab precision
98×98 mm panel pH transmitter
Panel ORP transmitter
144×144 panel conductivity monitor
Inductive non-contact conductivity
Panel turbidity, switchable window
Panel turbidity, low range
Fluorescence DO monitor, no consumables
BOD analyser, mercury-free
Representative families, not a complete catalogue. See all instruments or send us your application.
Other calculators on this site
The process design manual covers treatment train sizing — aeration, clarifiers, biological reactors, filtration, disinfection and sludge handling. The tools on this page sit one level upstream: they decide which instruments you need, before any process design begins.
These calculators return specification guidance, not quotations. Final instrument selection depends on temperature, pressure, mounting and chemistry compatibility. Conversion results are estimates with the accuracy limits stated on each page, and none of them substitutes for the measurement method named in your permit.
Cite this tool / 引用此工具
If you use this result in a report, specification or client document, please cite it as below. It takes one line and lets engineers find us. 如果您把计算结果用于报告、规格书或客户文件，请按下列方式引用。
Jiuyuhub. "Instrument Selection Calculators". Jiuyuhub, https://jiuyuhub.com/instrument-selection-calculators.html
Licensed for internal and commercial technical use (CC BY 4.0). 内容可用于内部及商业技术用途。 Questions? Ask our engineers