GE Optica, Operator'S Manual

Page: 38 / 150

Installation 2-17
January 2006
Model 1311DR Sensor
The 1311DR is a stainless steel, liquid cooled, four-stage sensor
suitable for measuring dew points between –75°C and +25°C.
Mount the 1311DR sensor so that the air inlet and exhaust openings
are free from obstruction (see Figure 2-17 below). If the sensor is
liquid cooled, vertical wall mounting is recommended, observing the
“UP” arrow on the case. This ensures that condensation forming on
cold portions of the 1311DR will drain from the enclosure.
At room temperatures (25°C) with air cooling, dew points from
–65°C to +25°C can be measured. When operating it without liquid
cooling, switch on the built-in fan. For lower frost point
measurements, a chilled-water coolant loop can be used for cooling.
Make sure the fan switch is off when using liquid cooling.
Sample flow rates from 0.5 to 5 standard cubic feet per hour
(0.25 to 2.5 liters per minute) should be used.
Caution!
If it can be avoided, do not operate the sensor
continuously at or near full depression. Doing so may
decrease the life of the thermoelectric heat pump.
Liquid cooling is required for measuring frost points below –65°C
(at 25°C ambient), and may be used to create faster response at higher
dew point temperatures. If a recirculating chiller is used, it should
have a capacity of at least 300 watts at the coolant temperature.
Switch the internal fan ON if air cooling is used; leave it OFF for
liquid cooling.
Install the gas sampling lines according to the instructions listed in
the section
Sampling Lines on page 2-13.
Figure 2-17: Model 1311DR Sensor