About ZeroAndSpan

Peter

Hi, I'm Peter — an Applied Electronics & Instrumentation Engineering graduate from a reputed university in Germany, currently working as a data analyst in the IT industry. ZeroAndSpan is where my two worlds meet: the instrumentation engineering I trained in, and the software and data skills I use every day.

Why this site exists

Every instrumentation engineer and technician knows the scrap-paper calculations: scaling a 4–20 mA signal, looking up a PT100 resistance, working out a DP range with zero suppression, checking whether a loop will even power up. The formulas are standard, but the online tools for them were scattered, cluttered with ads, or — worse — quietly wrong. I wanted one place where these calculations are done once, done right, and explained well enough that you can verify the math instead of trusting a black box. Zero and span are the two adjustments every instrument needs; getting them right is the whole craft in miniature. Hence the name.

How the calculators are built and verified

Every tool on this site states its formula, shows a worked example, and follows the applicable standard — IEC 60751 for RTDs, the ITS-90 reference functions for thermocouples, NAMUR NE 43 for signal limits, IEC 60534 conventions for valve sizing. Before a calculator goes live, its implementation is checked numerically against published reference tables (for example, the thermocouple functions are validated at dozens of table points across all eight types). Found an error anyway? Tell me — accuracy reports go to the top of the queue and get fixed fast.

A few things about me

New calculators are added regularly. If a tool you need is missing, write to me — reader requests decide what gets built next.

All tools are provided for reference and education — see the disclaimer. This site is supported by advertising, which keeps every calculator free to use.