Altek Model 934 Milliamp Voltage Loop Calibrator Manual

							PN 1886535 Rev A April 2002
©2002 Altek Industries, Inc. Specifications subject to change without notice.
All tights reserved. Printed in U.S.A.
Multifunction Loop Calibrator
Model 934 
						

							ORDERING INFORMATION               Part No.
MODEL 934 MULTIFUNCTION
LOOP CALIBRATOR                                             934
A carrying case is included with each Model 934
Contents
GENERAL INFORMATION......................................................... 2
YOUR NEW CALIBRATOR...................................................... 2
MILLIAMP CALIBRATION...................................................... 3
VOLTAGE CALIBRATION ........................................................ 3
QUIK-CHEK & AUTO-CHEK................................................... 3
GENERAL OPERATING INSTRUCTIONS.................................. 4
TURN ON................................................................................. 4
RESTORE DEFAULT SETTINGS............................................ 5
ENABLING RANGES & FUNCTIONS..................................... 6
AUTO-OFF .......................................................................... 6
% DP FLOW ........................................................................ 6
AUTO-CHEK ...................................................................... 6
ENGINEERING UNITS...................................................... 6
SETTING DIP SWITCHES...................................................... 7
RANGES.................................................................................. 8
CHANGING BATTERIES......................................................... 9
USING ENGINEERING UNITS............................................ 10
SOURCE MODE OPERATING INSTRUCTIONS.................... 14
STORING QUIK-CHEK
® OUTPUTS.................................... 16
RECALLING QUIK-CHEK OUTPUTS.................................. 16
SOURCE FUNCTIONS........................................................ 17
CALIBRATE MILLIAMP INPUTS..................................... 17
SIMULATE 2-WIRE TRANSMITTERS............................ 18
POWER & MEASURE 2-WIRE TRANSMITTERS.......... 19
CALIBRATE VOLTAGE INPUTS ...................................... 20
CALIBRATE LOOP CONVERTERS & ISOLATORS....... 21
CHECK 1-5 VOLT INPUTS WITHOUT
DISCONNECTING WIRES.............................................. 22
USING AUTO-CHEK....................................................... 24
READ MODE OPERATING INSTRUCTIONS........................... 28
MIN/MAX ............................................................................... 29
READ FUNCTIONS.............................................................. 30
READ MILLIAMP OUTPUTS.......................................... 30
READ VOLTAGE OUTPUTS ............................................ 31
SPECIFICATIONS...................................................................... 32
CALIBRATION PROCEDURE................................................. 38
WARRANTY............................................................................... 44
ORDERING INFORMATION...................................................... 45 
						

							1
FEATURES
• DUAL LIQUID CRYSTAL DISPLAY
Simultaneous Source and Read
• LABORATORY ACCURATE
±(0.012% of Reading + 0.008% of Full Scale Reading)
Accurate to ±0.004 mA from 4 to 20 mA
• USER SETTABLE “QUIK-CHEK®s”
Set any Span & Zero
• FULL FIVE DIGIT DISPLAYS
Source up to 24.000 mA, 20.000 V or 999.90 mV
Read up to 52.000 mA, 99.990 V or 999.90 mV
• SCALEABLE DISPLAY
Set in engineering units
• SPEED SENSITIVE DIGIPOT
Fast setting to any desired value
• “AUTO-CHEK”
TM OUTPUTS
Automatically outputs in 2, 3, 5 or 10 steps
• ISOLATED  SOURCE AND READ
Isolated to 500VDC
Fuseless protection to 120 V AC/DC
44
THREE YEAR WARRANTY
 Altek products are warranted to be free from defects in
material and workmanship (excluding fuses, batteries and
leads) for a period of one year from the date of shipment.
Warranty repairs can be obtained by returning the equipment
prepaid to our factory. Products will be replaced, repaired, or
adjusted at our option. 
Altek gives no other warranties, includ-
ing any implied warranty of fitness for a particular purpose.
Also, Altek shall not be liable for any special, indirect, incidental
or consequential damages or losses arising from the sale or use
of its products. 
						

							2
GENERAL INFORMATION
Simultaneously source and read any combination of
process milliamp and voltage signals. Alteks Model 934
combines all the functionality of a milliamp and a
voltage calibrator! This dual function calibrator continuously
displays the output and input signals. The top half of the
display indicates the output setting while the lower half of
the display shows the signal being measured.
Calibrate state of the art equipment such as smart
transmitters and indicators to 4
1/2 or more digits using the
Model 934. Full 5 digit resolution lets you check any brand of
process control equipment. Your calibrations are correct
with accuracy surpassing 0.02% of reading.
Use the scaleable display to match the readings on the
Model 934 to that of the equipment being calibrated.
For example, if your 4 to 20 mA recorder scale is 0.0 to
300.0 gallons/hour you can set the 934 to display 0.0 for 4 mA
and 300.0 for 20 mA. No more need to use your calculator
or cheat sheet to come up with the correct milliamp values.
Six AA alkaline batteries provide more than 20 hours
sourcing 20 mA continuously . . . more than 3 months of typical
use. From the time the low battery indicator first comes on you
have hours of power remaining to get you through a shift without
interruption. The 934 comes configured  to automatically power
down after 30 minutes of inactivity to save battery life.
Calibrate loop converters and isolators by simultaneously
providing the input signal and measuring the output of
the converter or isolator. Internal optoisolators withstand up to
500 VDC  between the source and read leads. Calibrate and
checkout all your process milliamp and voltage instruments
with the benchtop accurate Model 934.
YOUR NEW CALIBRATOR
43
CALIBRATION PROCEDURE
mV
1) Connect the Read leads to a voltage source and place
the DVM across the voltage source  (See below).
2) Turn the unit on and wait for the unit to go into calibration
mode (SOURCE and READ flashing).
3) Press the 
RESET pushbutton to select Read mode.
4)Dial the unit so mV is displayed press the RESET pushbutton.5) Set the voltage source to 0.00mV so that the DVM reads
0.000mV ±0.040mV and press the RESET pushbutton.
6) Set the voltage source to 999.90mV so that the DVM reads
999.90mV ±0.100mV and press the 
RESET pushbutton.
7) Turn the unit off.
V
1)
Leave the Read leads connected as in the mV calibration2) Turn the unit on and wait for the unit to go into calibration
mode (SOURCE and READ flashing).
3) Press the 
RESET pushbutton to select Read mode.
4) Dial the unit so V is displayed and press the RESETpushbutton to select V.
5) Set the voltage source to 0.000V so that the DVM reads
0.0000V ±0.0004V and press the 
RESET pushbutton.
6) Set the voltage source to 95.000V so that the DVM reads
95.0000V ±0.0019V and press the 
RESET pushbutton.
7) Turn the unit off.
READ MODE ADJUSTMENT
ALTEK 934
VOLTAGE
SOURCE
SOURCEREAD
DMM
After calibration has been
completed place the unit into
normal operating mode by
placing the CAL Enable
jumper  back into the stored
position (See figure page 38). 
						

							3
GENERAL INFORMATION
MILLIAMP CALIBRATION
Use at any point in your 4 to 20 milliamp loop. Source
milliamps directly into your receivers with loop loads up to 1200
Ohms. Simulate 2-Wire Transmitters for checkout of field
wiring and total loop testing. Power and measure
2-Wire or 4-Wire transmitters on the bench before installation.
Read Transmitter & Controller outputs up to 52.00 mA.
Display directly in milliamps, percent of 4 to 20 mA, percent
of DP Flow or engineering units to match the scale of
your process.
VOLTAGE CALIBRATION
Calibrate and checkout all your DC Voltage instrumentation.
Source up to 999.90 millivolts to simulate sensors and up to
20.000 Volts to check your process signal inputs.  Measure
voltages from -99.990 to +99.990 VDC to check your power
supplies and the outputs from any process voltage equipment.
Calibrate any 1 to 5 Volt device in a live 4 to 20 milliamp loop
without disconnecting any wires. The Model 934 will
automatically source or sink 0 to >16 milliamps to clamp the
test voltage in all source ranges. Output impedance is less
than 0.2 Ohm to let you calibrate voltage instruments in
milliamp loops without removing the input load resistors.
QUIK-CHEK & AUTO-CHEK
Instantly recall three output settings in each range with
the handy QUIK-CHEK switch. All output settings are
remembered for each function, even with the power off.
Use the AUTO-CHEK to continously switch the Model
934s output from Zero to Span in 2, 3, 5 or 10 equal steps
at intervals of 5 to 900 seconds. Leave behind the panel
and do your calibration from the front...or simulate your
2-Wire transmitter and calibrate every device in the loop.
42
CALIBRATION PROCEDURE
READ MODE ADJUSTMENT
mA
1) Connect the Read leads to a current source in series with
a 100 Ohm resistor. Monitor the current by placing a DVM
across the 100 Ohm resistor (See below).
2) Turn the unit on and wait for the unit to go into calibration
mode (SOURCE and READ flashing).
3) Press the 
RESET pushbutton to select Read mode.
4) Dial the unit so mA is displayed and press the RESETpushbutton.
5) Set the current source to 0.000mA so that the DVM reads
0.0000V ±0.000096V and press the Read store pushbutton.6) Set the current source to 24.000mA so that the DVM reads
2.4000V ±0.00024V and press the RESET pushbutton.
7) Turn the unit off.
ALTEK 934
CURRENT
SOURCE
SOURCEREAD
DMM
100 OHM 
						

							4
ROCHESTER NY 14623ALTEK 934SOURCE19.934mA
mA/V LOOP CALIBRATOROFF ONHI
SET
LOMAX
READ
MIN
9VDC
AUTO-CHEK HI
MINREAD0.000V
SOURCE
STOREQUIK-CHEK ®SETUP
READ
RESETSETUP
500
        MAXSOURCESOURCEREAD
OPERATING INSTRUCTIONS
GENERAL
TURN-ON
Each time the Model 934 is turned on,
the LCD will display all segments for about
1 second. It then displays the most recently
selected Source & Read Settings.
1) Move the power switch to 
ON.
All segments on the LCD are turned
on during self test.
2) The upper half of the LCD will indicate
if SOURCE is enabled while the lower
half will indicate if READ is enabled.
SOURCE - The three QUIK-CHEK outputs
will be the same as previously stored. Each
time a different function is selected, the
three QUIK-CHEK outputs for that function
will be recalled.
READ - The 934 is ready to measure the
same signal as the last time it was turned on
and is automatically updating the MAX &
MIN readings for recall from the READ
toggle switch.
CONNECTIONS
The Model 934 has built-in test leads
with alligator clips for attachment to
instruments or sensors with terminal
blocks or flying leads. 
To prevent acci-
dently overloading the instrument being
tested, it is important to correctly set up
the outputs before connecting the Model
934 to any instruments to be calibrated.
41
ALTEK 934SOURCEREAD
DMM
100 OHM
CALIBRATION PROCEDURE
SOURCE MODE ADJUSTMENT
mV
1) Connect the Source leads to the DVM (See below).
2) Turn the unit on and wait for the unit to go into calibration
mode (SOURCE and READ flashing).
3) Press the 
STORE pushbutton to select Source Mode.
4) Turn the knob until mV is displayed and press the STOREpushbutton.
5) Dial the output until the DVM reads 0.000mV ±0.040mV
and press the 
STORE pushbutton.
6) Dial the output until the DVM reads 999.900mV ±0.100mV
and press the 
STORE pushbutton.
7) Turn the unit off.
V
1) Leave the Source leads connected as in the mV calibration
2) Turn the unit on and wait for the unit to go into calibration
mode (SOURCE and READ flashing).
3) Press the 
STORE pushbutton to
select Source Mode.
4) Turn the knob unitl V is displayed
and press the STORE pushbutton.5) Dial the output until the DVM
reads 0.0000V ±0.0022V and
press the 
STORE pushbutton.
6) Dial the output until the DVM
reads 20.0000V ±0.002V and
press the 
STORE pushbutton.
7) Turn the unit off.
8) Disconnect the source leads
from the DVM. 
						

							5
OPERATING INSTRUCTIONS
GENERAL
FIELD & BENCH USE
The Model 934 comes with a carrying
case and a built-in tilt stand/hanger.
The 934 is held securely in the case
by VELCRO
® for use with the carrying
case open. The carrying case also has a
snap-on belt loop which can also be
looped around a pipe or rail.
    The tilt stand is easily raised by pulling
the stand until it locks into place. The
stand can also be reversed for use as a
hanger to suspend the Model 934.
RESTORE DEFAULT SETTINGS
The Model 934 may be restored to the factory default setting.
This will reset the HI and LO “QUIK-CHEK” memories according
to the table below and the SET memory to ,idrange below HI
and LO. The output and input are set to the mA range.
1) Press and hold  both the 
STORE& RESET push-buttons while
turning the Model 934 on.
2) Keep pressing the push-buttons
until the display flashes once
(10 seconds) then release.
3) All segments on the LCD will
remain displayed until the
Model 934 has been reset QUIK-CHEK DEFAULTS
RANGE      HI     LO
    mA         20.000 4.000
%4-20mA100.00 0.00
   %DP  100.0 0.0
     mV 100.00 0.00
      V         5.000 1.000
Note: Some ranges and functions are enabled by DIP
switches (see pages 6 & 7 for factory settings).
AUTOCAL
To maintain accuracy the Model 934 periodically recalibrates
its measuring circuitry against internal references. While this
is occuring the word CAL will appear on the LCD display for
less than 2 seconds.
VELCRO®  is a registered trademark of Velcro USA40
CALIBRATION PROCEDURE
SOURCE MODE ADJUSTMENT
2-Wire Sim
1) Connect the Source leads in series with the current source
set to 30 mA and the 100 Ohm resistor. Connect the DVM
parallel with the 100 Ohm resistor (See below).
2) Turn the unit on and wait for the unit to go into calibration
mode (SOURCE and READ flashing).
3) Press the 
STORE pushbutton to select Source Mode.
4) Turn the knob until 2-WIRE SIM is displayed and press the
STORE pushbutton.
5) Disconnect the positive output lead from the 100 Ohm
resistor and wait until the display reads 0.00 and press the
STORE pushbutton.
6) Re-connect the positive output lead to the 100 Ohm
resistor and dial the output until the DVM reads 2.4000V
±0.00024V and press the 
STORE pushbutton.
7) Turn the unit off.
ALTEK 934
CURRENT
SOURCE SET
AT 30mA
SOURCEREAD
DMM
100 OHM 
						

							6
OPERATING INSTRUCTIONS
ENABLING ADDITIONAL RANGES & FUNCTIONS
The Model 934 has two additional ranges for displaying % DP
Flow and Engineering Units. Additional  functions are AUTO-
CHEK (automatic stepping of outputs) and AUTO-OFF.
These ranges & functions are enabled by configuring DIP
Switches (see next page). After the functions are enabled they
are available as selections during setup (see OPERATING
INSTRUCTIONS, SOURCE or READ).
AUTO-OFF
The Model 934 can be set up to turn itself off after 30 minutes
of inactivity. The internal timer is reset to 30 minutes each
time the digital pot is turned or a pushbutton is pressed.
% DP FLOW
Check out the signal generated by DP (differential pressure)
flow transmitters, square root extractors or other signals using
a square law. Select %DP Flow for all milliamp functions.
AUTO-CHEK
The Model 934 can be set up to automatically step the output
with your choice of 2, 3, 5 or 10 steps from Zero to Full Scale.
ENGINEERING UNITS
Scale the display on the 934 to match the display of the
instrument being calibrated. For example if you have a digital
indicator showing 0.0 to 1000.0 Gallons/Hour from a flowmeter
with 4 - 20 mA output you can scale the output of the 934 to
display 0.0 at 4 mA and 1000.0 at 20 mA.
39
CALIBRATION PROCEDURE
SOURCE MODE ADJUSTMENT
mA
1) Connect the Source leads in series with the 100 Ohm re-
sistor. Connect the DVM parallel with the 100 Ohm resistor
(See below).
2) Turn the unit on and wait for the unit to go into calibration
mode (SOURCE and READ flashing).
3) Press the 
STORE pushbutton to select Source Mode.
4) Turn the Digital Pot (yellow knob) until mA is displayed and
press the 
STORE pushbutton.
5) Dial the output with the READ toggle switch in the MAX
position (coarse adjust) until the DVM displays approxi-
mately 0.0 V. Move the READ
toggle switch to READ (fine
adjust) until the DVM reads
0.0000V ±0.000096V and
press the 
STORE pushbutton.
6) Dial the output (using the
same coarse and fine adjust-
ments) until the DVM reads
2.4000V ±0.00024V and press
the 
STORE pushbutton.
7) Turn the unit off.To change the output of the Model 934 during the calibration
of the SOURCE functions both coarse and fine adjustments
are used.  Place the 
READ toggle switch in the MAX position
for coarse adjustment and move the READ toggle switch
to the READ position for fine adjustment.
ALTEK 934SOURCEREAD
DMM
100 OHM
If calibrating with an 81/2digit
multimeter directly in milliamps
the calibration points are0.000 mA
±0.00096mA and 24.000 mA±0.0024mA 
						

							BOTTOM BOARD
Calibrator Enabled
(Jumper Shorted)
on
off
CAL
7
OPERATING INSTRUCTIONS
ENABLING ADDITIONAL RANGES & FUNCTIONS
The DIP switches are located in
the battery compartment. Turn the
Model 934 off and loosen the three
slotted screws and remove the battery
cover.
38
CALIBRATION PROCEDURE
SUGGESTED EQUIPMENT
1) Digital voltmeter with accuracy of ±0.003% of reading at
2V and ±0.005% of reading at 100V
Important: The required accuracy is usually found
only on meters with 71/2  or more digits
2) 100 Ohm laboratory standard resistor with accuracy of
±0.003%
3) Adjustable DC Voltage source, 0 to 95.000 VDC with
resolution of 0.001 V and 0.01 mV
4) Adjustable DC current source, 0 to 24.000 mA with
resolution of 0.001 mA.
An 81/2Digit Multimeter with DC current accuracy of ±30 PPM
may be substituted for items 1 & 2 to calibrate the mA ranges
ENABLING CALIBRATION
Allow one hour for the Model 934 to
stabilize to the ambient temperature
of the calibration room. Remove the
battery cover and the 4 black phillips
head screws. While holding the 934
face down in one hand carefully
seperate the top and bottom of the
housing. Place the unit into calibration
mode by placing the jumper located
on the bottom board into the CAL
position.
During calibration the top half of the 934’s LCD display prompts
you with the input or output value being calibrated. The bottom half
indicates the measurement computed by the Model 934. When a
pushbutton is pressed to store a calibration reading the value in the
top half of the LCD flashes once. Please pause for 10 seconds before
proceeding for the 934 to compute the new calibration values.
Recommended calibration adjustments in this procedure have
been calculated  to 1/2of specification. See pages 36 & 37 for a table
of published specifications which may be used to obtain “As Received”
& “Adjusted” Test Data points.
*Factory default settings
4422AUTO-CHEK
Disabled AUTO-CHEK
Enabled*Engineering
Units Disabled* Engineering
Units EnabledENGINEERING UNITS
Switches between enabling and
disabling Engineering Units range
option for all functions AUTO-CHEK
Switches between enabling and
disabling AUTO-CHEK option for
source functionsAUTO-OFF
Switches between continuous
operation and automatic turn off
after 30 minutes of inactivityPERCENT DP FLOW
Switches between enabling and
disabling Percent DP Flow range
option for the milliamp functions
AUTO-OFF
Enabled*
Continuous
OperationPercent DP
Flow Enabled*
33
Percent DP
Flow Disabled
1(Switch
Up)1
(Switch
Down) 
						

							8
√
OPERATING INSTRUCTIONS
 RANGES
The selected range is displayed on the LCD by the
annunciators listed below.
MILLIAMPS - mA
Choose mA to display directly in milliamps. Display in SOURCE
and READ functions from 0.000 to 24.000 mA. In READ you
can also measure up to 52.00 mA.
PERCENT OF 4 - 20 MILLIAMPS - mA %
Choose mA % to display in percent of span for 4 - 20 mA loops.
Use with chart recorders or current trips that display in %.
0.00% 4.000 mA
25.00%8.000 mA
50.00%12.000 mA
75.00%16.000 mA
100.00%  20.000 mA
Percent =  (mA-4)/0.16 mA =  (Percent/6.25) + 4
PERCENT DIFFERENTIAL PRESSURE - % DP
Choose % DP to display in percent of the square law for 4 - 20
mA loops. Also use to calibrate square root extractors and other
square law mA inputs.
0.0%4.000 mA
25.0% 5.000 mA
50.0% 8.000 mA
75.0% 13.000 mA
100.0%20.000 mA
%DP = (   mA-4) x 25 mA = (%DP/25)2+ 4
VOLTAGE - V
Choose V to display directly in DC Volts. Use for  0 to 1 Volt, 1
to 5 Volt or 0 to 10 Volt signals. SOURCE from 0.000 to 20.000
VDC. In READ the 934 autoranges between -999.90 to +999.90
millivolts and -99.990 to +99.990 VDC.
37
Source Volts
   VOLT   LOW  HIGH
  OUTPUT  LIMIT  LIMIT20.000V 19.997 20.003
10.000 9.998 10.002
5.000 4.998 5.002
1.000 0.999 1.001
0.000 -0.001 0.001
Source Millivolts
   mV   LOW  HIGH
OUTPUT  LIMIT  LIMIT999.90mV 999.701000.10
500.00 499.86 500.14
100.00 99.91 100.09
10.00 9.92 10.08
0.00 -0.08 0.08
Read mA3
     mA   LOW  HIGH
  INPUT   LIMIT  LIMIT
52.00mA 51.99 52.01
30.00 29.99 30.01
24.000 23.995 24.005
20.000 19.996 20.004
12.000 11.997 12.003
4.000 3.998 4.002
0.000 -0.002 0.002
Read Volts3
   VOLT   LOW  HIGH
  INPUT   LIMIT  LIMIT
99.990V 99.970 100.010
50.000 49.986 50.014
20.000 19.997 20.003
10.000 9.998 10.002
5.000 4.998 5.002
1.000 0.999 1.001
SPECIFICATIONS
MODEL 934 RANGES AND ACCURACIES
Read % 4-20 mA
    mA       %4-20mA LOW     HIGH
INPUT  INPUT LIMIT   LIMIT
24.000mA 125.00% 124.97 125.03
20.000 100.00 99.97 100.03
12.000 50.00 49.98 50.02
4.000 0.00 -0.02 0.02
0.000 -25.00 -25.01 -24.99
Read % DP Flow
  mA         %FLOW LOW    HIGH
INPUT       INPUT LIMIT     LIMIT
20.000mA   100.0%DP 100.0 100.0
8.000 50.0  50.0 50.0
4.000 0.0  -1.2 1.2
3LOW & HIGH LIMITS are identical
for negative readings
1Simulate 2-Wire Transmitter range
is from 3.000 to 24.000 mA
2100 Ohm resistor is used in the
calibration procedure (Seepage 38)
Read Millivolts3
  mV   LOW  HIGH
INPUT   LIMIT  LIMIT
999.90mV 999.70   1000.10
500.00 499.86 500.14
100.00 99.91 100.09
10.00 9.92 10.08
0.00 -0.08 0.08