Everyone’s heard the old saying: you can’t manage what you can’t measure. But what if you can’t even measure what you’re measuring in the first place?

That’s actually a key problem with the sensors used to monitor and control today’s factories, data centers, offices and other buildings. The fact is, they go out of whack, both predictably over the course of years and unpredictably as the result of manufacturer errors, field exposure, or other factors.

In fact, most building system sensors can be expected to go out of calibration often enough to need replacement every few years, according to John Pitcher, a building controls expert and founder of Scientific Conservation, the building energy efficiency startup now called SCIenergy.

Earlier this year, Pitcher became CEO of Weber Sensors, a main-line German industrial sensor company, with the goal of bringing a new line of self-calibrating sensors to market to help solve this problem. Weber has filed patents on technology to recalibrate so-called calimetric flow and temperature sensors, and is working on patents for humidity sensors as well, he told me in an interview last month.

The goal is to build cell phone chipset-based microprocessors into sensors that can test themselves to see where their readings don’t jibe with reality, Pitcher said. That should be able to keep Weber’s new temperature sensors accurate to within less than half a degree Centigrade, in a provable fashion, for up to ten years, he said.

All the added IT will make Weber’s sensors about one-third more expensive than regular sensors, he noted. But he also expects that the multi-billion-dollar industrial and building controls sensor market will find the return on investment well worth the extra cost.

“People have to appreciate the cost of having inaccurate sensors,” Pitcher said. He first discovered the problem while working with customers of Scientific Conservation’s continuous commissioning and fault detection software, which relies on sensors for its data.

But sensors are built with technology that’s almost guaranteed to go out of true over time, he said. Temperature sensors, for example, use devices called thermistors (or electrical resistors) that change their resistance depending on the temperature, which are molecularly altered in the course of carrying that current, he noted. Humidity sensors, a critical component of outside-air cooling and other HVAC control systems, are notoriously unstable and aren’t expected to last more than two years or so, he said.

Weber’s new sensors solve that problem by testing themselves, using known variables, to compare the expected results against whatever the sensor is telling them, he said. For a temperature sensor, that might involve heating and then cooling over a specific time period -- something today’s dumb, analog sensors can’t do.

Pitcher said he knows of a few other companies working on self-calibrating sensors, including Accutech, AccuTru Sensor Technologies and Invensys. Of course, it’s quite possible that others in the building controls ecosystem are working on the problem. IT companies like IBM, Cisco and Echelon, startups like SkyFoundry, Viridity Energy and BuildingIQ, and big energy services companies (ESCOs) like Honeywell, Johnson Controls, Siemens, Schneider Electric, Emerson and the like, are all digitizing building control networks in ways that could allow them to analyze incoming data for calibration purposes.

But having a smart sensor at each end point could sure help. Pitcher said that he sees ESCOs as competitors, as well as potential partners, on the self-calibrating sensor front. Most of today’s building sensors are proprietary, analog devices with little or no ability to actually communicate digital signals, he added. Weber’s new sensors will do their own testing using their on-board microprocessors, but many will have to communicate their findings using today’s analog systems.

Pitcher didn’t name any specific customers that have signed up for the self-calibrating sensors the company is now working on, nor did he disclose how much internal investment he and the company have put into the R&D for the new products. But Weber is a well-established company in the sensors space, with plenty of existing customers that could provide good test beds.