November 2019

HOW EXERGEN'S NON CONTACT INFRARED TEMPERATURE SENSORS HELP ENSURE ACCURATE RESULTS IN HORTICULTURAL RESEARCH?

Exergen GlobaL's micro IRt/c temperature sensors are being employed by Netherlands-based Plant Lighting B.V. in its research aimed at reducing the artificial energy required to cultivate Phalaenopsis orchids in greenhouses. Orchid production, a $600 million industry in the Netherlands, requires a significant amount of energy for artificial light, heating and cooling. Through its research, Plant Lighting hopes to find new ways to reduce energy needs while increasing plant output.

Plant Lighting had previously used thermocouples in its research, but reported that the leaves’ diurnal (‘daily’) movements prevented the sensors from maintaining the constant contact required for accurate leaf temperature measurement. Moreover, the many small pores (‘stomata’) used by leaves for transpiration and CO2uptake, may differ in opening from one position on the leaf to the other. These differences can cause small local variations in leaf temperature, and therefore can require many thermocouples to accurately measure the leaves’ surface. Exergen’s non-contact micro IRt/c proved to be better suited for the research because they are able to measure a larger area of the leaf and provide the accuracy and reliability required for the research.

RELEVANT TECH NOTE #26: IRT/C REPEATABILITY AND LONG-TERM ACCURACY

The ability of the measuring device to maintain its calibration under service conditions and over a long period of time is of fundamental interest in temperature control. The IRt/c is rated at less than 0.1°C repeatability and has no measurable long term calibration change, which makes it well suited for reliable temperature control. These attributes are inherent in the basic design and construction of each IRt/c.

Repeatability is defined as the ability of a measuring device to reproduce its calibration under identical conditions. The IRt/c is a solid, hermetically sealed, fully potted system that does not change mechanically or metallurgically during service. There are no active electronic components and no power source to produce the signal – only the thermoelectric effects that produce a thermocouple signal. Long term accuracy is influenced by the same things that influence repeatability: mechanical changes and metallurgical changes. It is well known that thermocouples can change calibration over time due to these effects.

Read the full Tech Note here