20
Analog output signals of 0-5 Vdc and 4-20 mA are attained at the appropriate pins
of the 15-pin "D" connector (see
Figure b-1
) on the side of the XFM transducer.
Table VI
Analog Output Jumper Configuration
See APPENDIX IV for actual jumpers layout on the PCB.
6. MAINTENANCE
6.1 Introduction
It is important that the Mass Flow Meter is only used with clean, filtered gases.
Liquids may not be metered. Since the RTD sensor consists, in part, of a small
capillary stainless steel tube, it is prone to occlusion due to impediments or gas
crystallization. Other flow passages are also easily obstructed.
Therefore, great care must be exercised to avoid the introduction of any potential
flow impediment. To protect the instrument, a 50 micron (XFM 17) or 60 micron
(XFM 37/47/57/67/77) filter is built into the inlet of the flow transducer. The filter
screen and the flow paths may require occasional cleaning as described below.
There is no other recommended maintenance required. It is good practice, how-
ever, to keep the meter away from vibration, hot or corrosive environments and
excessive RF or magnetic interference.
If periodic calibrations are required, they should be performed by qualified per-
sonnel and calibrating instruments, as described in section 7. It is recommended
that units are returned to Aalborg® for repair service and calibration.
ANALOG SIGNAL
OUTPUT
0-5 Vdc
4-20 mA
Flow Rate Output
Jumper Header J7
J7.A
J7.B
J7.C
5-9
6-10
7-11
J7.A
J7.B
J7.C
1-5
2-6
3-7
Note:
Digital output (communication) is simultaneously available with
analog output.
,
CAUTION:
TO PROTECT SERVICING PERSONNEL IT IS
MANDATORY THAT ANY INSTRUMENT BEING SERVICED IS
COMPLETELY PURGED AND NEUTRALIZED OF TOXIC,
BACTERIOLOGICALLY INFECTED, CORROSIVE OR RADIOACTIVE
CONTENTS.
