Siemens Building Technologies QFM Series Data Sheet
Duct Relative Humidity/Temperature Sensors
QFM Series
QFM Series Duct Relative
Humidity Sensor.
Description
The QFM Series Duct Relative Humidity and Relative
Humidity/Temperature Sensors monitor and transmit
changes in humidity and temperature to the building
control systems. Several models are available for humidity
only (in 5%, 2% and 2% certied) or for humidity and
temperature sensing (also in 5%, 2% and 2% certied
versions). The humidity only units are available in either
4 to 20 mA or 0 to 10 Volt signal versions. Combination
humidity and temperature units are also available in either
dual current or voltage versions, transmitting proportional
signals back to the controller. Nickel 1000 Ohm (Siemens
type) or Platinum 1000 Ohm RTD (385 ALPHA type)
temperature outputs on combination versions are
also offered.
Features
• 4 to 20 mA or 0 to 10 Vdc output signals
• High degree of accuracy
• Removable, replaceable sensing tip
(2% and 2% certied models)
• Versions with LCD display also available
QFM Series Duct Relative Humidity and
Relative Humidity/Temperature Sensor.
Applications
The QFM Series Duct Relative Humidity and Relative
Humidity/Temperature Sensors are especially suited for
applications where precise, stable humidity sensing
is required.
E-27
Sensors
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QFM Series Specifications
E-28
Sensors
General
Installation ................................... 18 AWG cable length shared in conduit
with other sensor wiring 750 ft. (229 m) max
Connections ................................................................... Screw Terminals
Dimensions
Probe ................................. 0.6" O.D. x 7.2"L (15 mm O.D. x 183 mm L)
Housing ..3.1" L x 2.3" W x 1.5" O.D. (80 mm L x 60 mm W x 40 mm D)
Voltage Requirement .................................................. 13.5 to 35 Vdc and
24 Vac (for sensors with 0-10 Vdc outputs)
Input Impedance (4 to 20 mA versions only) ........... Less than 500 Ohms
Housing Material Type .............Polycarbonate plastic, UL 94-5VB rated,
suitable for plenum installations
Housing Protection Class ................. IP 65 (QFM3xxx, QFM4xxx types),
IP54 (QFM2xxx types), NEMA 1 (all types)
Filter Material and Specication .......................... Teon, 10 micron lter
Agency Certication........ UL listed to UL 873 for Temperature Indicating
and Regulating Equipment
CE Conformance ............. EC Directive on electromagnetic compatibility:
89/336/EEC
Humidity Element
Operating Range ................................................................. 0 to 100% RH
Measurement Range ............................................................ 0 to 95% RH
Accuracy at Room Temperature ≈ 73°F (20°C):
All types: ............................ ±5% RH, 0-95% RH (±3% RH, 30-70% RH)
±2% RH, 0-95% RH
Operating Temperature Jumper Selectable ....... 32 to 122°F (0 to 50°C)
or -31 to 95°F (-35 to 35°C)
or -31 to 140°F (-35 to 60°C)
Temperature Effect .....................................Less than 0.1% per degree C
Sensing Element............................. Capacitive humidity sensing element
Output Signal
RH only units ..................... 4 to 20 mA and 0 to 10 Vdc, 0-100% Linear,
Proportional
RH/T units ..............................0 to 10 Vdc, 0-100% Linear, Proportional
Polarity Protection...............................................................................Yes
Temperature Element Specifications (for Combination RH/T Units Only)
QFM2110 (Platinum)
QFM2120 (Nickel)
Operating Temperature -31 to +140°F (-35 to +60°C) -31 to +122°F (-35 to +50°C) -31 to +158°F (-35 to +70°C)
Time Constant Approximately 20 seconds in moving air
+/-0.6K — — 59 to 95° F (15 to 35°C)
Accuracy +/0.8K 59 to 95ºF (15 to 35ºC) 59 to 95ºF (15 to 35ºC) 31 to 158ºF (-35 to +70ºC)
+/-1.0K 31 to 140°F (-35 to +60°C) -31 to +122°F (-35 to +50°C) —
Output Signal
Calibration None
Platinum 1K Ohm RTD (385) 0 to 10 Vdc (QFMx160)
Nickel 1K Ohm RTD (Siemens) 4 to 20 mA (QFMx171)
QFM2160
QFM2171
QFM31xx
QFM41xx
QFM Series Product Ordering
Application Description Part No.
Duct Humidity 5% 0 to 10 Vdc QFM2100
Duct Humidity 5% 4 to 20 mA QFM2101
Duct Humidity 5% & Temperature 0 to 10 Vdc / Temp 1K Ohm Platinum RTD (385 alpha) QFM2110
Duct Humidity 5% & Temperature 0 to 10 Vdc / Temp 1K Ohm Nickel RTD (L&S Type) QFM2120
Duct Humidity 5% & Temperature 0 to 10 Vdc / Temp 0 to 10 Vdc QFM2160U
Duct Humidity 5% & Temperature 4 to 20 mA / Temp 4 to 20 mA QFM2171
Duct Humidity 2% 0 to 10 Vdc QFM3100
Duct Humidity 2% 4 to 20 mA QFM3101
Duct Humidity 2% & Temperature 0-10 Vdc / Temp 1K Ohm Platinum RTD (385 alpha) QFM3110
Duct Humidity 2% & Temperature 0 to 10 Vdc, Temp 0 to 10 Vdc QFM3160
Duct Humidity 2% & Temperature 0 to 10 Vdc, Temp 0 to 10 Vdc, w/Display QFM3160D
Duct Humidity 2% & Temperature 4 to 20 mA / Temp 4 to 20 mA QFM3171
Duct Humidity 2% & Temperature 4 to 20 mA / Temp 4 to 20 mA, w/Display QFM3171D
Duct Humidity 4 to 20 mA (Certied) QFM4101
Duct Humidity & Temperature 0 to 10 Vdc, Temp 0 to 10 Vdc (Certied) QFM4160
Duct Humidity & Temperature 4 to 20 mA / Temp 4 to 20 mA (Certied) QFM4171
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