Basic operation
1.
Power Switch
-
when switched on the CAL-2 performs
internal self-checking procedures. During this short period a
sequence of numbers are displayed.
2.
Output Level Selector
- provides for rapid selection
between three set-points:
Full-scale
(10V or 20mA) and
Zero
( 0V or 0mA)
fixed set-points, and the variable
Dial
setting.
NB for generating raised zero signals the Dial setting may be
used.
3.
Dial
- provides variable outputs across the output ranges
0 - 10.22V or 0 - 20.44mA (
0.2% FSD ± 2 digits
). To facilitate
rapid transition across the output range, dial speed is
increased 10-fold when the dial is pressed whilst turning.
The last dialled output value is retained in memory when the
CAL-2 is switched off. - this can be particularly useful for
storing a raised zero value. e.g. 4mA.
4.
Output Mode Selector
-
selects between
mA Source
,
mA
Sink
and
Voltage output
.
5.
External Power socket
- for use with the optional universal
AC mains power supply (part no. CAL-2-PSU). When the jack
is inserted the battery supply is disconnected.
I
O
+
COM
Stroud Instruments Ltd www.sil.co.uk
SIL
CAL-2
mA / Volt Calibrator
Power
12V
DC
mA Source
Full-scale
Zero
Dial
Volts
C
mA Sink
(2-wire
transmitter simulator)
+
1
3
2
5
4
Installing / replacing batteries
The CAL-2 mA / Volt Calibrator requires 4off Type AA (LR6,
MN1500, HP7) alkaline dry batteries. Replace the batteries when
the display indicates 'LOW BATTERY'.
To install batteries:
1. Turn off the power switch
2. Disconnect test leads
3. Remove the protective boot
4. Locate the battery
compartment cover on the
rear of the instrument, press
down as shown and slide off
the cover.
5. Note the polarity of the
batteries and fit as shown
(NB the polarity is embossed
on the floor of the
compartment)
.
6. Replace battery
compartment cover and
protective boot.
Mains power supply option
Only the optional universal mains power supply (part no.
3144-0012) should be used for this purpose. Switch off the
CAL-2 before connecting the power supply.
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Examples
1. Voltage test signals required: 0V, 5V and 10V
Set Output Mode Selector to 'Volts'
Set Output Level Selector to 'Dial'
Adjust dial to set output to 5.00V
Use Output Level Selector to switch between full-scale (10V),
dial (5V) and zero.
2. mA test signals required: 4mA and 20mA
Set Output Mode Selector to 'mA Source' or 'mA Sink'
Set Output Level Selector to 'Dial'
Adjust dial to set output to 4.00mA
Use Output Level Selector to switch between full-scale
(20mA) and dial (4mA).
mA Source mode
In mA Source mode the CAL-2 provides the power source to
drive the current loop. Use this mode for passive (non-powered)
circuits (for powered current loops see
mA Sink mode
).
Do not apply any external voltage to the output terminals in this mode -
this may result in damage to the CAL-2
For your personal safety and to avoid damage to the CAL-2, always
ensure that the external circuit is voltage free before connecting test
leads.
Please note: the CAL-2 displays a direct reading of the output
signal. With current output modes, in the event of an open circuit
loop, e.g. the instrument not connected or a loop fault exists, the
display will read '0.00'.
I
O
+
COM
Stroud Instruments Ltd www.sil.co.uk
SIL
CAL-2
mA / Volt Calibrator
Power
12V
DC
mA Source
Full-scale
Zero
Dial
Volts
C
mA Sink
(2-wire
transmitter simulator)
+
Alarm A
www.sil.co.uk
500-TT Process display
Alarm C
Alarm B
+
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Switch the Output Mode
selector to 'mA Source'
