CIE 542 also defines 0-10 V for short distances (<15 m) in electrically quiet environments and 0-20 mA for some legacy systems. However, 4-20 mA became dominant.
If we assume CIE 542 relates to a publication or standard within the CIE's catalog:
Because "CIE" primarily handles illumination (International Commission on Illumination), many assume CIE 542 covers photometry. This is a false cognate. In process control contexts, particularly in older European textbooks, CIE 542 is strictly analog signaling. cie 542
If you need the definitive specification for CIE 542, you must look under its current designations:
Many university libraries and IHS Markit (now part of S&P Global) hold the historical CIE 542 document. For most practical purposes, the IEC 60381 series is the legally authoritative replacement. CIE 542 also defines 0-10 V for short
A CIE 542-compliant loop must reject common-mode noise up to 100 V RMS (50/60 Hz) and series-mode noise of 10 mV peak-to-peak without exceeding ±0.1% error.
In 2025, with HART, Foundation Fieldbus, Profibus PA, and Ethernet-APL becoming widespread, why should a modern engineer care about a standard whose number (CIE 542) is nearly obsolete? Many university libraries and IHS Markit (now part
Statistics tell the story: According to a 2023 ARC Advisory Group study, over 65% of installed process instrumentation points in refineries, chemical plants, and water treatment facilities still communicate exclusively via 4-20 mA analog signals. That represents tens of millions of active loops.
The reasons are compelling:
Even when using digital HART communication, the underlying physical layer remains a CIE 542-compliant 4-20 mA analog signal. Remove the HART modem, and the analog value still works perfectly.