There is certainly training available for CCTV engineers but as yet
no formal qualifications, either City and Guilds or NVQs. SITO is
currently working on a formal qualification but it is not yet available
and could be some time before it is. In the meantime we have to do with
videos, lecturing, etc. but no really structured courses.
Many years ago in about nineteen canteen I remember discussing
with Mike Tennant, who was with Tavcom and then Gyyr, the amount of
hype and misinformation that abounded in the CCTV industry. ( Still my
hobbyhorse today). In particular the total lack of training available
apart from some manufacturers. The problem with manufacturers training
is that it obviously is centred around their products and still
includes a considerable content of sales pitching. Many things have
changed over the years, especially the technical support provided by
manufacturers. However even they get frustrated at the number of times
they are called out to apparent problems with their products, only to
find it is often some totally unrelated problem, like incorrect
terminations.
So, when Mike Tennant said that he was going to set up a
training company, Tavcom Training, I wondered whether he was going to
put his money where his mouth used to be! The company has now been set
up for several months now and I thought it would be an idea to see what
progress had been made in this void in the industry.
Mikes intention was to set up training in an innovative and
practical manner. There is great emphasis placed on practical hands-on
sessions in between the theory. The training room is pleasantly
informal and limited to ten delegates. With more than ten people Mike
found that the practical sessions could not be effectively managed.
Adjacent to the training room is a workshop kitted out with the usual
range of test equipment including an oscilloscope, light meter, power
supplies, etc. At the other end is a room fitted out with a wide rang
of CCTV components. There are several examples of multiplexers,
monitors, VCRs, matrix switchers, quad units, transmission systems,
etc. This is where delegates can actually program multiplexers, set up
time lapse VCRs, program matrices and interconnect all different
configurations. The equipment in this room represents a huge investment
plus items kindly provided by many manufacturers.
It is interesting to note that Tavcom Training are the only
company certified by IPSA to issue certificates of competence in CCTV
to delegates passing an approved written examination. There are
currently two, two day courses available, a basic introduction to CCTV
for engineers new to the industry with little or no knowledge of CCTV.
The other is an advanced CCTV course for more experienced engineers and
for those who have passed the basic course. Tavcoms’ policy is not to
issue certificates of attendance because they are pretty meaningless in
terms of what a delegate has learned. Those who achieve a pass mark of
50% at the end of the course receive a certificate from IPSA, those who
don’t, get nothing except 10% discount off a repeat course! The basic
course must be passed to qualify for acceptance on the advanced course.
The most impressive aspect of the training set up is the
balance between theory and practice. During the workshop sessions,
delegates actually get to carry out such activities as ;
- Setting up monitors.
- Looping through and setting terminations. Seeing the result of incorrect termination.
- Using an oscilloscope to measure video signals.
- Fit lenses to cameras and connect auto iris lenses.
- Back focus cameras with zoom lenses.
- Fit and test BNC connections.
- Set up Time lapse VCRs and program 24 hour mode and set to switch to 3 hour on alarm input.
- Select and connect power supply units.
- Calculate lens fields of view.
- Understand Operational Requirements and the use of the Rotakin.
- Set up and program several types of multiplexer.
For the evening of the first day, delegates, are given a simple
system to design and specify using a distributors’ catalogue to select
the most appropriate components.
Another interesting mini project is that a subject is set at
about 50 Metres away, and they have to calculate the lens to provide a
given percentage of the subject on the screen. A camera is then set up
with the selected lens and displayed on a monitor to see the actual
result of the selection. Sometimes with surprising results!
There is an optional extra day offered devoted to fault finding
in the workshop and demonstration room. During this day the delegates
are required to connect up various items of equipment which may or may
not be faulty. Mike has acquired quite a few nasties for this day, such
as auto iris lenses with incorrect wiring, cameras with the back focus
not working, providing a C-mount lens with a CS-mount camera and many
others to test the resources of trainees to determine and correct the
fault.
Can you score 50%?
Ql Each frame of video information is made up of 2 fields, how many fields are there per second? (Monitors - 2 marks)
Q2 How many lines of information are contained in a CCIR video picture, is it 50, 312 or 625? (CC TV - 2 marks)
Q3 If you intend to install Qty 2 - 500 Waft floodlights off the
same fused spur, what rating of fuse should you use? (Health &
Safety - 2 marks)
Q4 In CCTV terminology, what do the letters CCD stand for? (Cameras - 2 marks)
Q5 Modern cameras may use either "C" or "CS" mount lenses. Which of the following statements is true to ensure correct focusing?
A) A 'CS' mount lens can be fitted to a 'C' mount camera provided a 5mm Collar is fitted.
B) A 'C' mount lens when fitted with a 5mm collar can be used with a 'CS' mount camera.
C) A’CS’ mount lens can be fitted to a’ CS’ mount camera provided that a 5mm collar is used. Lenses - 2 marks
Q6 Coaxial cable is a most common method of video transmission.
Using RG59 cable, what losses, in percentage, are typical over a 200
metre run of this cable. (Cables - 2 marks)
Q7 When focusing a camera fitted with a zoom lens, what is the
recommended procedure for setting accurate tracking focus from narrow
angle to wide angle view? (Lenses -5 marks)
Q8 Modern cameras v,/ill operate on one of three input voltages, what are they? (Power supplies - 3 marks)
Q9 The electronic signal generated by a camera is known as the
composite signal and has an industry standard of 1 volt peak to peak.
What are the voltage levels for:
Sync............White..........Black............ (Cameras - 6 marks)
Q10 What unit of measurement is used to measure the amount of light available at the scene to be viewed? (Lighting - 2 marks)
Ql1 In CCTV terminology what do the letters PSU denote? (Terminology - 2 marks)
Q12 When using an oscilloscope, what time setting should the
oscilloscope be set to in order to display the composite video signal
waveform so as to view two fields simultaneously? (Test equipment 4
marks)
Q13 What is the standard termination impedance (Ohms) for CCTV equipment? (Monitors & cables - 2 Marks)
Q14 When using a time-lapse video recorder in a 24hour mode,
what is the recommended number of times a VHS cassette tape should be
used before replacing it? (Tape management 2 marks)
Q15 What is the recommended ratio, base width in relation to height, when using a scaffold tower? (Health & safety2 marks)
Q16 The measurement of light is expressed in nano Metres. When
choosing an lnfrared light for covert use. ( Not able to see the red
glow) what filter type should be used. Is it 715nM, 85OnM, or 5OnM?
(Lighting - 2 Marks)
Q17 What does the expression "OR" denote when compiling a site survey? (Site surveying- 2 Marks)
Q18 Y-C is an expression used when using S/VHS video recorders.
What do the letters Y-C denote? Y............C..............(Video
recorders 2 marks)
Q19 A camera housing used in an external position should be
selected with an IP rating. What is the minimum IP rating required?
(Housings2 marks)
Q20 When connecting a video picture from one monitor and
looping through to another monitor, which position is the Hi-Z / 75 Ohm
switch set to on the first monitor? (Monitors & cabling 2 marks)
How did you get on?
Ql Sketch the waveform, indicating the elements of a video composite
signal and the voltage levels. (cameras & CCTV introduction - 10
marks)
Q2 Describe how to use a lens calculator. (Lenses 5 marks)
Q3 Explain vertical interval switching. (switchers 10 points)
Q4 RG 59 Coaxial cable is a common cable used in CCTV
installations. What approximate losses are incurred over 250 Metres.
Your answer may be expressed in dB or percentage terms. (Cables 5
marks)
Q5 When using an oscilloscope, what time setting should the
oscilloscope be set to in order to display the composite video signal
waveform so as to view two fields simultaneously? (Test equipment 5
marks)
Q6 What is the standard termination impedance for CCTV equipment? (Monitors & cables - 2Marks)
Q7 Explain conditional refreshment techniques. ((Video transmission 10 marks)
Q8 Explain the principles of video time share multiplexing.(video multiplexer IO marks)
Q9 In video motion detection applications, list 5 common
problems associated with unwanted alarms. (Video motion detection 10
marks)
Q10 Sketch a six camera system and the interconnections
required to operate as a matrix switcher - configuration 6 camera
inputs and two monitor outputs. (matrix switching 10 marks)
Ql1 Give three methods of transmitting camera control telemetry. (telemetry 6 marks)
Q12 Explain on which telephone network system1 1. A modem is used. 2.A terminal adapter is used(Video transmissions 4 marks)
Q13 Describe a ground loop and what steps must be taken to correct the problems encountered. (Cables IO marks)
Q14 Give four current technology principles for providing video transmission by telephone networks. (Video transmission 8 marks)
How did you get on with that one? Note that some of the questions
may have been duplicated in these examples, in practice the questions
set to all delegates are recorded to prevent such repetition. Also
there is a large bank of questions from which a selection is made for
each course
I now think, not only has Mike put his money where his mouth was but
has achieved a significant breakthrough in expanding education in this
desert if CCTV knowledge. I also believe that this is setting the
standard for future training in the industry. Having said that, there
is still a great deal of development in the training of CCTV system
designers needed.
With the facilities and wide range of equipment installed it seemed
a natural idea to fill yet another gap in the industry knowledge base.
This is, objective, comparative testing of similar products. The first
project is already under way, which is comparative tests on seven
different multiplexers. The signals from four cameras were fed
simultaneously to all the multiplexers and each multiplexer recorded
onto identical individual time lapse VCRs. Both live pictures and
replays of recordings could be viewed on individual monitors. The full
range of tests will include, subjective evaluation of picture quality,
actual field update time, measurement using specialised test equipment,
the benefits of Y/C outputs where available, ease of programming, ease
of making connections and looping through, readibility of installation
and user manuals, etc. It is hoped that the results may be published in
the next issue of CCTV today. Plans are in hand to continue testing
phoneline transmission systems, cameras, digital recording, domes and
anything that is generally confused by manufacturers‘ specmanship’.
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