RTI MAS-1 User manual

User's Manual - English - Version 2019.12A
RTI Electronics Inc.
33 Jacksonville Road, Bldg. 1,
Towaco, NJ 07082
USA
Phone: [phone] (Toll free)
Int. [phone]
E-mail
Sales: [e-mail]
Support: [e-mail]
Service: [e-mail]
Web: http://www.rtigroup.com
Contact Information -
United States
RTI Group AB
Flöjelbergsgatan 8 C
SE-431 37 MÖLNDAL
Sweden
Phone: Int. [phone]
E-mail
Sales: [e-mail]
Support: [e-mail]
Service: [e-mail]
Web site: http://www.rtigroup.com
Contact Information -
World-Wide
RTI Group AB reserves all rights to make changes in the RTI MAS-1 and the information
in this document w ithout prior notice.
RTI Electronics AB assumes no responsibility for any errors or consequential damages
that may result from the use or misinterpretation of any information contained in this
document.
Copyright © 1993-2019 by RTI GroupAB. All rights reserved.
Content of this document may not be reproduced for any other purpose than supporting
the use of the product w ithout prior permission fromRTI.
Invasive Tube Current Probe Adapter
RTI MAS-1
RTI article number: 9630509-00

Contents
2
RTI MAS-1 User's Manual 2019.12A
Together w ith instruments fromRTI Group AB it is to be used for independent
service and quality control, as w ell as measurements of kerma, kerma rate, kVp,
tube current, exposure time, luminance, and illuminance w ithin limitations stated
below .
If installed according to accompanying documents, the product is intended to be
used together w ith all diagnostic X-ray equipment except for:
- therapeutical X-ray sources.
- X-ray equipment w ith tube potential below 20 kV.
- X-ray equipment on which the instrument cannot be mounted properly, e.g.
equipment where the beamfield size is narrow er than the active part of the
detector.
- specific types of X-ray equipment listed in the instructions for use or in additional
information fromthe manufacturer.
With the X-ray installation in stand-by conditions w ithout patients present, the
product is intended to be used:
- to provide the operator w ith information on radiation beamparameters that might
influence further steps in an examination but not an ongoing exposure.
- for assessing the performance of the X-ray equipment.
- for evaluation of examination techniques and procedures.
- for service and maintenance measurements.
- for quality control measurements.
- for educational purposes, authority supervision etc.
The product is intended to be used by hospital physicists, X-ray engineers,
manufacturer's service teams, and other professionals w ith similar tasks and
competencies. The operator needs a short training to be able to use the product as
intended. This training can be achieved either by careful study of the manual,
studies of the built-in help function in measurement softw are or, on request, in a
course provided by the manufacturer.
The product is intended to be used inside X-ray rooms ready for clinical use and
can safely be left sw itched on and in any measuring mode in the vicinity of
patients.
The product is NOT intended to be used:
- for direct control of diagnostic X-ray equipment performance during irradiation of
a patient.
- so that patients or other unqualified persons can change settings of operating
parameters during and immediately before and after measurements.
Intended Use of the RTI MAS-1

RTI MAS-1 User's Manual2019.12A
Contents 3
Table of Contents
............................................................................................................. 41. INTRODUCTION ..................................................................................................... 41.1 APresentation of the MAS-1
............................................................................................................. 52. FUNCTION AND CONNECTION
..................................................................................................... 52.1 Connection of the RTI MAS-1
..................................................................................................... 62.2 Batteryand Charging
............................................................................................................. 73. MEASUREMENTS..................................................................................................... 73.1 Measurements of the mAs and mA Value
..................................................................................................... 73.2 Hints and Trouble-shooting
............................................................................................................. 94. SAFETY PRECAUTIONS
..................................................................................................... 94.1 General Rules
............................................................................................................. 105. SPECIFICATIONS
..................................................................................................... 105.1 General Specifications for RTI MAS-1
............................................................................................................. 11Index
For a full description of the Piranha or Cobia, see the Piranha or Cobia
Reference Manual.
That Manual can be found on the Product USB or be downloaded from RTI's
website (www.rti.se).
Note!

1. INTRODUCTION
A Presentation of the MAS-1
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4
1 INTRODUCTION
A Presentation of the MAS-11.1
The RTI MAS-1 probe provides an invasive way to measure mA and mAs on X-ray
equipment. The current probe should be connected to the X-ray mAs socket. It is
connected in series with the tube current ground return line of the high voltage
transformer.
The tube current feeds a 2.2 ohm resistor and the voltage drop is measured and
converted to a signal suitable for the Piranha or Cobia. RTI MAS-1 should be used
only on those generators providing open and short circuit protection of the measuring
circuit and where the circuit operates not more than 90 Vabove or below ground
potential.
The probe has a built in second order low pass filter with a bandwidth of 500 Hz. The
probe accept floating current input of 90 Vrelative to the ground level which makes it
accept most manufacturers’ current signals.
The RTI MAS-1 can measure from 0,1 mAto 3000 mA, when used together with the
Piranha or Cobia. By using Free-run or Timed update modes the RTI MAS-1 is able to
measure even lower.
CAUTION:
Users of mAs meters must be aware of the potential damage to generators
and electrical human hazards in the case of improper connection or failure
of anypart of the meter circuit. The MAS-1 is intended for use only bythose

1. INTRODUCTION
A Presentation of the MAS-1
RTI MAS-1 User's Manual2019.12A
5
skilled in the calibration and repair of X-ray machines. Please read the
section SAFETYPRECAUTIONS for more safetyrules.
2 FUNCTION AND CONNECTION
Connection of the RTI MAS-12.1
Please be aware that high voltage mayexist if the mAprobe connection is not properly
made. Read the SAFETYPRECAUTIONS chapter before you start measuring!
· Power down the X-rayunit and turn OFF the RTI MAS-1.
· Connect the RTI MAS-1 to the mAs measuring socket using the included safety
cables. Please observe the polarity(see picture below).
Caution!
Users of mAs meters must be aware of the potential damage to
generators and electrical human hazards in the case of improper
connection or failure of any part of the meter circuit. The MAS-1 is intended
for use only by those skilled in the calibration and repair of X-ray
machines. Please read SAFETY PRECAUTIONS for more safetyrules.
· Now connect the RTI MAS-1 to the detector input of the Piranha or Cobia using the
included cable. Attach the round Lemo female connector to the connector that is
9
9
9

2. FUNCTION AND CONNECTION
Connection of the RTI MAS-1
RTI MAS-1 User's Manual 2019.12A
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marked Output on the probe, and the other end to the electrometer input on your
meter.
· Turn ON the RTI MAS-1 using the grey rocker switch on the back panel, by pushing
the top part of the switch.
The green LED will now indicate that the RTI MAS-1 is powered ON. If the red “LoBat”
LED lights up, it indicates that the battery voltage is low. Please recharge the RTI
MAS-1 before measuring. See Batteryand charging .
Battery and Charging2.2
The RTI MAS-1 uses a built in rechargeable battery which you charge using the
standard mini-USB connector at the back of the probe. You can use either:
· a USB cable and charge it from your computer
· the charger that came with your Piranha
· or a standard USB charger with an output of +5 V.
Finally you need to flip the power switch to Off/Charge.
Note that you cannot use the RTI MAS-1 while it is charging. If the yellow LED at the
back is lit it indicates that the battery is charging. When the yellow LED switches off
the RTI MAS-1 battery is fullycharged. Normally onlya few minutes of charge is
needed to be able to measure for an hour or two.
6

2. FUNCTION AND CONNECTION
Battery and Charging
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The batterycannot be over-charged, since the RTI MAS-1 contains a charging
controller.
3 MEASUREMENTS
Measurements of the mAs and mA Value3.1
Setup the RTI MAS-1 according to the section Connection of the RTI MAS-1 . Power
on the RTI MAS-1 and then the Piranha or Cobia.
Start the QABrowser, as described in the QABrowser manual. and then select the
appropriate Real-time Meter display, e.g. tap Measure, Radiography, Tube Current,
(for the Barracuda you must also choose the EMM module) to be able to read the
current. It is typically shown in the unit "mA".
Tap Reset, then "0" should be displayed.
The offset adjustment procedure for Piranha or Cobia is finished and the RTI MAS-1
is ready for measurements.
Now just perform an exposure and the QABrowser will show you readings of tube
current (mA) and tube charge (mAs). You may also study the tube current waveform by
tapping the Wave button. The Piranha or Cobia starts to measure when the mA signal
is greater than approximately 0.1 mA when using the RTI MAS-1. For long exposure
times, you may want to switch to the Continuous update mode. The QABrowser will
then update the display continuously during the exposure. (See Settings in the
Piranha or Cobia manual).
Note that when using a PC connected to mains and and at the same
time a cable to the Piranha or Cobia, ground loops may arise that
generates ground currents that affects the measurements. It is
recommended to either connect wirelessly between the PC and meter,
or run a laptop PC on battery.
Hints and Trouble-shooting3.2
· If no current can be measured, please check the direction of current, Piranha or
Cobia CANNOT measure negative current.
· The most common cause of failure to measure correctly is incorrect connection to
the X-ray generator, usually to the tube filament circuit.
· Please use "All" and put the Piranha or Cobia in the X-ray field to “gate” the
measurements if it is a problem to hold the mAs value when using the single tube
current mode. This may happen because of current noise from the rotating anode
engine.
· An 8 meter extension cable EXT-1 is available if needed, to further extend the
cable.
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3. MEASUREMENTS
Hints and Trouble-shooting
RTI MAS-1 User's Manual 2019.12A
8
· Agood rule is that the mA waveform should be studied whenever checking the mA
station.
Large inaccuracy can arise when small values are measured if the mA waveform
information is not available.
If the value is lower than 10 mAs, special attention must be drawn to how the
charge supplied to the capacitance in the high voltage cable will influence the
measuring result. See picture below.
The easiest wayto do this is to use the oRTIgo/Ocean waveform analyser.
Selected values: 100 kV, 80 ms and 10, 25, and 50 mA. The upper part of the right picture shows the radiation intensityresponse from
the detector. The lower part of the figure shows the tube current measured with MAS-1B. Note especiallythe last part of the exposure.
Large mAs errors can be made if this part cannot be avoided. The left picture shows that the high voltage cables act as capacitors and
can influence the mAs measuring result.
· Note that when using a PC connected to mains and and at the same time a cable
to the Piranha or Cobia, ground loops may arise that generates ground currents
that affects the measurements. It is recommended to connect wirelessly between
the PC and meter, or run a laptop PC on battery.

4. SAFETY PRECAUTIONS
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9
4 SAFETY PRECAUTIONS
General Rules4.1
Onlyuse the RTI MAS-1 if you are authorised to make invasive measurements using
the X-ray generator mAs measuring socket.
• Please be aware that high voltage mayexist on the RTI MAS-1 if the cable
connection between RTI MAS-1 and the X-raygenerator mAs socket is broken.
• Always switch off the X-ray generator and wait approximately one minute
before you make any connection or disconnection of the cables between RTI MAS-1
and the mAs measuring socket.
• Always check that the short circuit path normally connected to the mAs
measuring socket is connected after the use of the RTI MAS-1 and before the X-ray
unit is switched on again.
• Do NOT connect the RTI MAS-1 to the filament current circuitry. The RTI MAS-
1 is only intended to measure the tube mA and mAs.
• Do NOT use the RTI MAS-1 in contact with a patient.
• Do NOT use RTI MAS-1 on a circuit with voltage higher then 90 V DC.
• Do NOT expose the instrument to direct sunlight, extremes of temperature
and humidity, or dew fall.
• Do NOT exceed maximum tube current input.
• Do NOT forget to turn the power switch off after use.
· Do NOT use the RTI MAS-1 on a circuit with a voltage of higher than
600 V AC.
Note!
The RTI MAS-1 is intended for service and qualitycontrol of diagnostic X-ray
equipment. It is not intended for use during or together with diagnostic
examinations of patients.
RTI Electronics AB takes no responsibilityfor misuse of the RTI MAS-1 or use
together with products that the RTI MAS-1 is not intended for.
RTI Electronics AB assumes no responsibilityfor customers not following these
safetyprecautions.

4. SAFETY PRECAUTIONS
General Rules
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5 SPECIFICATIONS
General Specifications for RTI MAS-15.1
Specifications are valid after a warm-up time of one minute and presuming reference
conditions.
Reference conditions
Temperature
20 °C
Relative humidity
50 %
Specifications
Current range
0.1 - 3000 mA
Charge range
0.001 - (at least) 9999 mAs
Inaccuracy
±1 % or ±0.01 mA
Frequencyrange, bandwidth
DC - 500 Hz(-3 dB)
Random error
1 %
Voltage over-protection limit
90 V nominal
Impedance / Load to generator socket
2.2 ohm
Scale/calibration factor
0.45 nA/mA(version 3)
Operating temperature
and relative humidity:
15 - 30 °C
at <80 % relative humidity
Storage temperature
-10 °C to +50 °C
Accepted maximum floating input range:
(Max common mode voltage)
90 V relative to X-ray generator
ground
Batterytype
Li-Ion, 1100 mAh
Weight
125 g
Dimensions
60×35×72 mm
Batterylife
Around 2 years of typical use or 100 hours