OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors Description Technical changes reserved 0141 0315-199 09/2014 B+B Thermo-Technik GmbH | Heinrich-Hertz-Straße 4 | D-78166 Donaueschingen Fon +49 771 83160 | Fax +49 771 831650 | info@bb-sensors.com | bb-sensors.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors Table of contents 1 General dangers and precautions 3 1.1 Dangers and precautions about the salt solutions 3 1.2 Important application notes 3 2 General description 4 3 Operating principle 4 4 Application guidelines 5 4.1 Intended use 5 4.2 Checks before application 5 4.3 Ambient conditions 5 4.4 Storgae conditions and durability 5 4.5 Temperature dependence 6 4.6 Tolerance and accuracy 6 4.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors 1. General dangers and precautions Please read the following precautions carefully before putting into operation! The symbols used in the operating manual are to make you careful, before hand, regarding safety considerations and dangers. But all these symbols cannot substitute the text of the associated safety instructions in any way. Therefore, the instructions should also be always read completely! ! 1.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors 3. Operating principle The operating principle is based on a saturated salt solution over which a particular value of relative humidity gets adjusted. For this purpose, it is important, that the solution is properly saturated i.e. both un-dissolved salt in crystalline form is available in the solution and liquid is also visible above that.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors 4.3 ! Ambient conditions In order to achieve maximum accuracy, it is recommended that the activity should be carried out in a laboratory room. The measurement and calibration area should be air-conditioned. The ambient temperature should be within 23 °C ±2 K and relative humidity in the environment should be within 50 % ±5 % RH. The closed styrofoam container can also be used to improve the temperature stability.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors 4.5 Temperature dependence In the most frequently used Lithium chloride, Magnesium-chloride and Sodium-chloride salts, the effect of temperature on humidity values is practically nil. Details of temperature dependence are as per the humidity tables provided in the appendix section of this documentation.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors ! 4.10 CAUTION! The cleaning with distilled water is permitted only for sensors. Resistive or electrolytic humidity sensors get seriously damaged beyond repair through water contact and needs to be replaced! Humidity sensors of other manufacturers are normally not water resistant and can get damaged through water contact.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors Close the cap of polystyrene container and wait for at least two hours. Put the device into operation. You can read the measurements on the display panel and assess stability at the adjustment point. Start adjustment only if the values on the display vary less than 0.1 % RH in a span of 30 minutes. After this, first you can start with the adjustment. Measure the ambient temperature in the vicinity of reference cells.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors 8. Warranty Congratulations on the purchase of this high quality product! The quality of our products is constantly monitored within the framework of our Quality Management systems as per ISO 9001 standards.
OPERATING INSTRUCTION Humidity reference cells for adjustment of humidity sensors 9. Salt tables (summary)* Salt Lithium chloride LiCl Temp.
