General description, Power supply options, Measured parameters – ROTRONIC HF5 User Manual
Page 6: Calculated parameters, E-m-hf5-v2_12, 3general description, 1 power supply options, 2 measured parameters, 3 calculated parameters

E-M-HF5-V2_12
Rotronic AG
Bassersdorf, Switzerland
Document code
Unit
HygroFlex HF5 Humidity Temperature
Transmitters: User Guide
Instruction Manual
Document Type
Page
6 of 36
Document title
© 2009-2013; Rotronic AG E-M-HF5-V2_12
3
General description
3.1 Power supply options
Depending on the circuit type, the HF5 requires the following power supply:
a) HF52 (2-
wire loop powered, analog outputs): 10…28 VDC - depending on the load connected to the
output(s). The minimum supply voltage can be determined as follows:
V min = 10 V + (0.02 x Load*) *Load resistance in ohms.
For the maximum load of 500 , the minimum supply voltage is 10 + (0.02 x 500) = 20 VDC. With both
output circuits closed, the maximum current consumption is 40 mA.
b) HF53, HF54 and HF56 (3-wire, analog outputs optionally combined with a digital output):
- HF53: 15 to 40 VDC or 12 to 28 VAC
- HF54: 9 to 36 VDC or 7 to 24 VAC, galvanic isolation of the analog outputs and power supply
- HF56
: 85…240 VAC, galvanic isolation of the analog outputs and power supply
HF53 and HF54: with both output circuits closed, the typical current consumption is 100 mA.
HF56: typical current consumption <50 mA at 85 VAC and <35 mA at 240 VAC
Please verify the product identification label to determine which power supply option is installed on your
transmitter.
c) HF556, HF557 and HF566 (digital output only):
- HF556: 5 to 40 VDC or 12 to 28 VAC
- HF557: PoE (power over Ethernet).The HF557 is not available with a RS-485 interface and can be
powered only via a LAN.
- HF566
: 85…240 VAC
Typical current consumption
HF556 with USB interface
: 100 mA
HF556 with Ethernet (TCP/IP) interface and HF557 : 300 mA
HF566 USB interface
: <50 mA at 85 VAC and <35 mA at 240 VAC
HF566 with Ethernet (TCP/IP) interface
: <50 mA at 85 VAC and <35 mA at 240 VAC
3.2 Measured parameters
The HygroClip 2 probe used with the HF5 transmitter measures relative humidity with a ROTRONIC
Hygromer
®
IN1 capacitive sensor and temperature with a Pt100 RTD.
3.3 Calculated parameters
Using the ROTRONIC HW4 software, the HF5 can be configured by the user to calculate one of the following
parameters:
o
Dew point (Dp) above and below freezing
o
Frost point (Fp) below freezing and dew point above freezing
o
Wet bulb temperature (Tw)
o
Enthalpy (H)
o
Vapor concentration (Dv)
o
Specific humidity (Q)