Tequipment 7005 User manual

7005 Loop Calibrator
Technical Manual

1 Contents
1. Introduction …………………………………….. 2
2. Operation ..........................................................3
2.1 Front panel controls..................................3
2.2a Current loop connections..........................4
2.2b Voltage loop connections..........................5
2.3 On/Off control ...........................................6
2.4 Selecting Source or Measure mode..........6
2.5 Selecting Current or Voltage.....................6
2.6 Source Mode ............................................7
2.6a Current source..........................................8
2.6b Voltage source..........................................9
2.6c Output control ..........................................10
2.6d Manual Step / Inching...............................10
2.6e Auto-Step..................................................11
2.6f Ramp ......................................................12
2.6g Output errors.............................................13
2.7 Measure Mode..........................................14
2.7a Current measure.......................................15
2.7b Voltage measure.......................................16
2.7c Min/Max readings.....................................16
3. User setup
3.1 Auto power-down.......................................17
3.2 User programmable range and ramp.........18
4. Specification.....................................................20
5. Battery and recharging....................................22
6. Guarantee and service.....................................23

2
1. Introduction
The 7005 is a micro-processor based instrument for the
calibration of voltage and current loop signals. It can operate in
three modes,
a) Loop current/voltage source (simulating a transmitter and
the loop supply)
b) Sink of loop current (simulating a transmitter)
c) Measurement of loop current/voltage (simulating a loop
indicator).
Display is via a dot matrix LCD screen. User input is by 7 front
panel buttons.
Source functions are a) Manual step, b) Auto step c) Ramp. In
step function there are five calibration points, 0%, 25%, 50%,
75% and 100% of span. In ramp function the output ranges
between 0% and 100% of span the ramp rate and dwell time are
user programmable.
In source mode the range can be user programmed for any
values between 0mA to 50mA, or 0V to 21V. For example a low
point of 10mA and a high point of 50mA could be set giving a
span of 40mA
In measure mode only fixed ranges are available. Current and
voltage is displayed in 5-digit format in mA or Volts. Alternatively
the current may be displayed in % of span.
An internal NiCad battery can power the unit for up to 9 hours.
Recharge is available via an external mains powered unit. The
display will indicate ‘Low Batt’ when the unit needs to be
recharged. An automatic power-down feature is incorporated
and turns the unit off after approximately 7 minutes if no buttons
are pressed. If required the automatic power-down feature can be
disabled in the user set-up.
The unit is constructed in an impact resistant ABS case and
connections are made via 4 off 4mm binding terminal posts.

3
Selects one of the
following 5 ranges,
User programmed
4 - 20 mA
0 - 20 mA
Sqrt 4 - 20mA
Sqrt 0 - 20mA
When in Source
and manual step
mode, steps up
and down
When in Source
and inching
mode, moves
output up and
down
When in Source mode,
toggles between ramp
and manual step
When in Measure
mode, displays Min
and Max values
Press to toggle
between Measure
and Source mode
Press and hold for
power ON and OFF
Short press for
User Setup
2.1 Front panel controls
When in Source
mode, press and
hold for ‘inching’
When in Source mode,
press both together for
auto step
When in Measure
mode, toggles
between V and mA
Note: A short press on the (ON/OFF) button. The button
functions change and are indicated by the adjacent black legends.
Move cursor right.
Increment digit.
Scroll through options.
Save setting.

4
2.2a CURRENT loop connections:
Loop current
indicator
10.00mA
+
—
Loop current
indicator
10.00mA
+
—
24V Loop
power supply
+
—
Source: Unit supplying loop power and setting loop current.
Sink: Unit setting loop current
+
—
Measure: Unit supplying loop power while measuring loop current
Pressure
+
—
7005 measuring loop current. Loop
power from external supply.
Pressure 24V Loop
power supply
+
—
Transmitter
TX
Transmitter
TX
Measure: Unit measuring loop current, loop power external

5
2.2b VOLTAGE loop connections:
Loop voltage
indicator
5.00V
+
—
Source: Unit setting loop voltage
+
—
Measure: Unit measuring loop voltage.
Pressure Transmitter
TX

6
2.3 ON/OFF Control
• To turn the unit ON, press and hold down the
ON/OFF button until the display powers up.
• To turn the unit OFF, press and hold down the
ON/OFF button until the display blanks.
2.4 Selecting Source or Measure Mode
• Turn the unit on.
• By pressing the ‘Source / Measure’ button the unit
can be toggled between source mode and
measure mode.
Source mode
selected Measure mode selected
2.5 Selecting Current or Voltage
Please note that changing between voltage and current can
only be done in Measure mode.
• Pressing the ‘Source / Measure’ button to
change in to Measure mode.
• Press the ‘V / mA’ button until ‘V’ or ‘mA’ is
displayed on the screen

7
2.6 Source mode
The unit can be operated as either a current source or a
voltage source. When calibrating current loops, the internal
24V power supply may be used to provide the drive voltage.
Alternatively, when the loop is externally powered, the unit
provides a sink function. Operation of the unit in both source
and sink is identical. However the connections made to the
terminals differ (see chapter 2.2).
Source mode Desired output
(mA)
Selected calibration point
(0%, 25%, 50%, 75% or 100%)
Actual output (% of span)
Selected
range
Manual step
Typical source display

8
2.6a Current source
Selection of range
• Switch the unit on.
• Ensure unit is in a mA range, see chapter 2.5.
• Select Source mode, see chapter 2.4.
• Press the ‘Range’ button to step though
the available ranges,
4 to 20mA
0 to 20mA
sqrt 4 to 20mA
sqrt 0 to 20mA
User programmed range
Note that the first four ranges above are indicated on the display
to the right of the word RANGE. When the User programmed
range is selected, ’USER’ is shown on the right of the word
RANGE.
4 to 20mA
range 0 to 20mA range
sqrt 4 to 20mA
range sqrt 0 to 20mA range
User programmable
range

9
2.6b Voltage source
The unit can operate as a voltage source up to a maximum of
21V at 20mA.
Connection is made via the COM and V+ terminal.
Please note that these are the same terminals used for voltage
measurement and it is therefore recommended that all leads
are disconnected when changing from Source to Measure
mode. See chapter 2.2 for connection details.
See chapter 2.5 to select voltage operation.
See chapter 2.4 to select source mode.
Only the user programmable range is available in voltage
source operation.
Desired output
(V)
Selected calibration point
(0%, 25%, 50%, 75% or 100%)
Actual output (V)
User programmable
range
Manual step
Typical Voltage Source display

10
2.6c Output Control
The unit provides three methods of controlling the output,
1) Manual step, 2) Auto-step, or 3) Ramp.
2.6d MANUAL STEP
Provides manual control of the five preset calibration point 0%,
25%, 50%, 75% or 100% of span. The output can also be fine
adjusted (inched) to provide an indication of the deviation from
the calibration point.
• Switch the unit on
• Ensure the unit is in Source mode (current or
voltage) as required (see chapter 2.4 and 2.5)
• Select range as required (see chapter 2.6a/b)
• The user can move up and down the steps by
pressing the ‘Inc’ or ‘Dec’ button
INC / DEC (1uA resolution) - Inching
• Hold down the ‘Min/Max’ button press either
the ‘Inc’ or ‘Dec’ buttons to adjust the output
in 1uA steps
If the ‘Inc’ or ‘Dec’ buttons are held down, the rate
of inching will increase after a short period
+
Selected step
(0%, 25%, 50%, 75% or 100%)
Manual step
enabled

11
2.6e AUTO-STEP
Provides automatic stepping with a programmable dwell period
between each steps.
• Switch the unit on
• Ensure the unit is in Source mode (current or
Voltage) as required (see chapter 2.4 and 2.5)
• Select range as required (see chapter 2.6a/b)
• To start the Auto-Step, press and hold the
‘Inch’ button followed by a short press of
the ‘Ramp’ button
• To stop the Auto-Step press the ‘Ramp’
button
+
Auto-step
enabled Output is currently in dwell state Output is increasing to next calibration point

12
2.6f RAMP
Provides a continuous ramp, with a programmable dwell period at
the top and bottom.
• Switch the unit on
• Ensure the unit in current or voltage source as
required, see chapter 2.4 and 2.5
• Select range as required, see chapter 2.6a/b
• To start the ramp, press the ‘Ramp’ button.
• To stop the ramp, press the ‘Ramp’ button
again.
Ramp
enabled Output currently in
dwell state
Unit is currently
ramping up
Unit is currently
ramping down

13
2.6g Output errors
When the unit is unable to provide the desired output due to
output error conditions, the display will show up arrows in
place of the digits.
Output error conditions are typically,
A) Loop resistance too large (current source)
B) Loop resistance too small (voltage source)
C) External loop supply voltage too low (current sink)
Desired value

14
Selected range
Measured value (mA, V or %)
Measure
mode
2.7 Measure Mode
When in measure mode, current or voltage is displayed in either
mA, Volts, or %(of span).
Additionally maximum and minimum readings can be displayed.
Typical measure display

15
2.7a Current Measure
The unit can measure current up to 125mA via the COM and
mA terminals. For see chapter 2.2 for connection details.
Selection of range
• Switch the unit on
• Select measure mode, see chapter 2.4
• Select a mA units, see chapter 2.5
• Press the ‘Range’ button, to step through
the available ranges,
4 to 20mA displayed in %
0 to 20mA displayed in %
sqrt 4 to 20mA displayed in %
sqrt 0 to 20mA displayed in %
0 to 125mA displayed in mA’s
Note that the selected range is indicated on the display to
the right of the word RANGE.

16
2.7b Voltage Measure
The unit can measure voltage up to +/-25V. Auto-ranging allows
full resolution (5 digits) for measurements lower then +/- 5V.
• Switch the unit on
• Select Measure mode, see chapter 2.4
• Select Volts units, see chapter 2.5
• Apply a shorting link between V+ and
COM terminals.
• Press the ‘Range’ and ‘Inc’ buttons
simultaneously to zero the reading
• Remove shorting link and connect signal to
be measured, -ve to COM and +ve to V+.
See chapter 2.2
2.7c Min / Max Readings
To display the minimum and maximum readings in mA, V or %.
• Press the ‘Min / Max’ button
Please note due to space limitations on the display the min and
max values for voltage are shown without decimal points
+
Minimum value
(-25% = 0mA) Maximum value (49.03% = 11.85mA)

17
3. User setup
The unit is fitted with non-volatile memory to store user set
values.
3.1 Automatic power-down
An automatic power-down feature is incorporated and turns the
unit off after approximately 7 minutes if no buttons are pressed.
If required the automatic power-down feature can be disabled.
• Switch the instrument ON.
• Select Measure mode.
• Press the 'Esc' button
• The display will now show,
OR
Auto power-down enabled Auto power-down disabled
• To toggle the Auto power-down press the
'Range' button
• Press the 'V / mA' button to store this value.
• Press the ‘Esc’ button to return to the
measure mode.

18
3.2 User programmable range and ramp
• Switch the unit on.
• Ensure the unit is in Source mode (current or
voltage) as required (see chapter 2.4 and 2.5).
Please note that the user settings stored in
mA function is separate to the settings in
Volts function.
• Using the ‘Range’ button select the user
programmable range. See chapter 2.6a/b
• Press the ‘Esc’ button, to enter user setup
• The user can step through the user settings by
pressing ‘Inc’ and ‘Dec’ buttons.
The user settings are displayed as,
0% Set low end of user range in mA or V.
100% Set high end of user range in mA or V.
mA.V/S Set ramp rate in mA or V per second.
T1 Set dwell period for ramp and auto-step in
seconds.
• To change a user setting move the cursor
underneath the digit that you wish to change
using the ‘Source / Measure’ button
• Press the ‘Range’ button the scroll though
available digits.

19
• Once the digits have been changed to the desired
value press the ‘V / mA’ button to store the setting.
The display will then return to the first user setting
(0%)
• Select the next user setting and change as required.
• To exit the user setup and return to normal
operation press the ‘Esc’ button.
Example - Setting a range of 10 to 40mA with slow ramping
Cursor
Currently selected digit
A low end of 10.000mA A high end of 40.000mA
A dwell time of 20
seconds
A ramp rate of 0.5 mA per
second