Bruker BioSpin NMR BVT3200, Техническое руководство

Страница: 19 / 56

Technical Manual Version 002 BRUKER BIOSPIN 19 (55)
LN
2
evaporator
LN
2
evaporator 2.3
This device is a cold nitrogen gas generator for low temperature experiments. The
nitrogen gas is produced by evaporating the liquid nitrogen contained in a dewar.
The power delivered to the heater, controlled by software, may reach 210 Watts
(approx. 38 V on a 7 ohm heater). The cold gas is transferred to the probe trough
a flexible and isolated transfer line.
For this device, an option printed circuit (PC) must be installed in the BVT3200. It
delivers the power applied on the LN
2
heater. The LN
2
level in the dewar is
continuously monitored by the VTU.
This PC has the part number W1101455. It is plugged on the main board of the
BVT3200 and is retainded by four plastic spacers.
Temperature accuracy is unchanged.
WARNING : The BSMS/2 must be equipped with a 48V/400VA power supply
(Z002840) to use the LN
2
evaporator option. When a standard 48V/200VA power
supply is present in the rack, the rear side must be unscrewed and removed to
replace the power supply located beside the BVT3200.
Evaporator presentation 2.3.1
Figure 2.2. Evaporator principle
Heater
Liquid nitrogen
Dewar tank
Refill level sensor
Empty level sensor
Transfer line
Cold N
2
out
Cable to BVT3200