ROTRONIC HF4 - Manual (Page 22)

E-M-HF4-V1_22
Rotronic AG
Bassersdorf, Switzerland
Document code Unit
HygroFlex HF4 Humidity Temperature
Transmitters: User Guide Instruction Manual
Document Type
Page 22 of 29
Document title
© 2009-2011; Rotronic AG E-M-HF4-V1_22
8 Maintenance
8.1 Service cable
IMPORTANT:
o Use service cable AC3009 with all 2-wire, loop powered transmitters. This cable powers up the
transmitter via the service connector. Do not use any other method for powering the transmitter when
using this cable AC3009 as this will create a ground loop and damage the transmitter. For the same
reasons do not use cable AC3006 with a 2-wire, loop powered transmitter.
o Use service cable AC3006 with all 3-wire transmitters as well as with digital models. This cable does
not provide power to the transmitter and the transmitter should powered separately when using this
cable
Both cables AC3006 and AC3009 convert UART (service connector) to USB and are used to connect the
transmitter to a USB port of a PC running the ROTRONIC HW4 software. Prior to using any of these
cables, the ROTRONIC USB driver must be installed on the PC. Both the driver and the installation
instructions (document E-M-HW4v3-Main) are located on the HW4 CD.
As an alternative, cable AC2001 is used to connect the HF4 to a probe input of the HP23 hand-held
calibrator. For service purposes, the HP23 offers essentially the same functionality as the HW4 software.
8.2 Location of the service connector (mini USB type)
WARNING: the service connector is a UART interface with a mini-USB connector type. Do not connect the
service connector directly to the USB port of a PC or hub.
The service connector can be accessed without opening the enclosure after removing the small red sealing
cover.
8.3 Periodic calibration check
Both the Pt 100 RTD temperature sensor and associated electronics are very stable and should not
require any calibration after the initial factory adjustment.
Long term stability of the ROTRONIC Hygromer humidity sensor is typically better than 1 %RH per year.
For maximum accuracy, calibration of the HF4 should be verified every 6 to 12 months. Applications
where the HF4 is exposed to significant pollution may require more frequent verifications.
HF32
Vertical mount: the service connector is
located either on the left side or on the
right side of the enclosure.
Horizontal mount: the service
connector is located at the bottom of
the enclosure (black arrow)