The Hungarian Emperor’s crown was exhibited in the Hungarian Parliament in 1999 after extensive restoration and has been accessible by the public since. This extremely valuable national treasure is protected in a free-standing display case provided by the German firm Glasbau Hahn, Frankfurt a. Main.

Since this exhibit contains various precious metals like gold, silver and platinum as well as organic materials like mother of pearl and easily oxidising materials like iron clamps and rivets, it must be conserved in an oxygen poor yet moist environment. The oxygen level is reduced by permanent nitrogen rinsing through an atmospheric exchange system. But since this nitrogen is provided from pressurized gas bottles, it must be retrospectively moisturized before introduction to the display case. The organic dyes used to colour the textiles and the artistically painted embellishments of the sceptre and crown on the other hand are highly light sensitive and may not be illuminated with any more than 270 Lux of UV-free light. Monitoring the storage conditions and ensuring a rapid response to any deviations from acceptable parameters dictated the use of an independent system additional to the elaborate climate control mechanisms and integrated into the pedestal of the display case. This monitoring unit we designed based on the RSM TRF 01 DeLUX hand measurement device integrated with an RS485-Data module and external power supply in the existing setup.

The internal monitoring unit gathers all relevant data on the display case environment like oxygen concentration, illumination strength, relative humidity and temperature. The data so gathered are transmitted via data link to the guard room of the Parliament where they are analyzed, put on ongoing display and archived with the help of a PC. Should any of the allowable tolerances be exceeded, an alarm is sounded on the PC. Due to the sensitivity of the secured area, remote monitoring was not considered. Notice of condition to the personnel responsible for the exhibit is provided by the security patrol on duty. Maintenance of both climate control and exhibit monitoring is only possible at particular times, with security supervision and for limited periods due to the necessary deactivation of the alarm system. In order to ensure adequate maintenance nonetheless, the sensors for illumination strength, relative humidity and temperature were manufactured in the same form and installed in the display case from below using sealing sleeves. The residual oxygen sensor, which is the most maintenance intensive element of the facility can be screwed off a threaded ring, adjusted on the device and reinstalled in a few minutes without having to open the display case. Every channel of a measurement value reader can be separately disconnected from the alarm during maintenance. In this way the measurement of the unaffected areas can continue without interruption.

 

 

 © 2007, Krah & Grote