(2) 100 degrees F span: Outside air, hot water, heating coil
discharge air, mixed air sensors
(3) 200 degrees F span: High temperature hot water, heating hot
water, chilled/hot water system sensors.
b.
Pressure:
(1) -0.5 to 0.5 [-0.25 to 0.25] inches water differential range:
static pressure control of rooms
(2) 0 to 5 inches water differential range: Duct static pressure
(3) 0 to 60 psig [0 to 100 psig] [0 to 200 psig] differential:
Water differential pressure
c.
Relative Humidity:
(1)
10 to 90 percent minimum relative humidity range
2.2.3
Relative Humidity Transmitters
Provide integral humidity transducer and transmitter. Output of relative
humidity instrument shall be a 4 to 20 mA or 0 to 10 VDC signal
proportional to full range of relative humidity input. Accuracy shall be 2
percent of full scale, long-term stability shall be less than one percent
drift per year. Sensing element shall be polymer type.
2.2.4
Pressure Transmitters
Provide integral pressure transducer and transmitter. Output of pressure
instrument shall be a 4 to 20 mA signal proportional to the pressure span.
Accuracy shall be 1.0 percent. Linearity shall be 0.1 percent.
2.2.5
Current Transducers
Provide current transducers to monitor amperage of motors. Select current
transducer for normal measured amperage to be near 50 percent of full-scale
range. Current transducers shall have an accuracy of one percent and 4 to
20 mA or 0 to 10 VDC output signal.
**************************************************************************
NOTE: Choose between CO2 sensors and air quality
sensors, or use both. CO2 sensors provide
information to ensure adequate ventilation. Air
quality sensors are very useful to monitor areas
that are vulnerable to organic contaminates like car
exhaust and industrial solvents.
**************************************************************************
2.2.6
Air Quality Sensors
2.2.6.1
CO2 Sensor
Provide CO2 sensors with integral transducers where shown. Output signal
shall be 4 to 20 mA or 0 to 10 VDC. Accuracy shall be +5 percent of full
scale.
SECTION 15910N
Page 37
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