Altek Model 235 Process Voltage Analyzer Data Sheet User Manual

							Process Voltage Analyzer
Model 235
• Calibrate voltage instrumentsSimulate Inputs
Check Outputs
• Three ranges with 0.05% accuracy0.0 to 199.9 Millivolts
0.00 to 19.99 Volts
-25.0 to 199.9% of 1 to 5 Volts
• Calibrate live voltage input receiversNo need to disconnect loop
• “Quik-Chek®” switchSet HI & LO outputs to match your Span & Zero
Instantly switch between HI & LO outputs
• Automatic overload protectionWithstands 120V AC or DC without fusesCalibrate and check out all your DC voltage
instrumentation with Altek’s Model 235 Process
Voltage Analyzer. Source from millivolts to 20 VDC
and measure your process voltage signals with this
single pocket sized instrument
Display your readings with 0.1% resolution from 0.0 to
199.9 millivolts, 0.00 to 19.99 Volts or from -25.0 to
199.9% of the 1 to 5 Volt signal. Accuracy is ±0.05%
of span.
Source voltage
Built-in batteries calibrate high or low impedance
voltage or millivolt instruments. Accuracy is
maintained to devices requiring up to 30mA. Three
nine volt alkaline batteries provide 100 hours of use
into high impedance loads. An optional AC adapter
plugs in for continuous bench use.
Instantly recall three output voltages
User adjustable Quik-Chek switch provides instant HI
and LO settings in source mode. DIAL position selects
a continuously adjustable potentiometer. Full 10 turns
with high resolution allows fast, easy setting to any
exact value.
Calibrate live circuits
Automatically calibrate live circuits without
disconnecting wires. Circuit sinks up to 20mA to
clamp test voltage in all ranges. 1 to 5 Volt devices in
live 4 to 20mA loops can be calibrated without any
effect on the other instruments in the loop.
Measure voltages
Precisely measure positive and negative voltages in
the 100mV and 10V ranges. 0 to 100% is displayed in
the 1 to 5 Volt range for checkout of process control
instruments. High input resistance (>2 Megohms)
minimizes loading effect on signals. Special protective
circuitry withstands misconnection to 120V AC in any
mode without fuses.
Display digits are 0.35 (9mm) high for readability
from across the room. Non-glare liquid crystal display
is readable in any light…even in direct sunlight. The
digital measuring circuit is independent and measures
the actual input or output.
The Altek Model 235 is rugged, yet lightweight and
pocket sized. Backed by a three year warranty, the
Model 235 is toolbox tough. Latest LSI circuitry and
wide temperature range components make the Model
235 ideal for use in the field, control room and shop.
Benchtop accuracy in a toolbox calibrator assures
fast, precise setting of trips, recorders, controllers,
loggers, computers and analysis instruments. Altek
brings you the handy Model 235 Process Voltage
Analyzer at a cost low enough for every check-out
and maintenance person.
General description 
						

							PN 1886496 Rev A April 2002
©2002 Altek Industries, Inc. Specifications subject to change without notice. 
All rights reserved. Printed in U.S.A.  
Altek products are warranted to be free from defects
in material and workmanship (excluding fuses,
batteries and leads) for a period of three years 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, including 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.
Warranty
Unless otherwise Indicated, specifications are in % of Span @ 23° C
Accuracy: ±(0.05% of Span + 1 Least Significant Digit)
Display: Liquid Crystal; 31/2 digit, 0.35 (9.0mm) high
Negative voltages: Measured on 100mV and 10V ranges
“Quik-Chek” Factory preset at 0% and 100% (1 and 5V)
ADJUSTMENT RANGE LO HI
20 Volts 0.10V to +1.50V       0.75V to 11.00V
Percent 1 to 5 V -25.0% to +12.0%    -10.0% to 199.9%
200 Millivolts -2.0mV to +25.0mV  10mV to 199.9 mV
Batteries: 3 x 9 Volt alkaline are included
Battery life: Nominal 100 Hours, Sourcing into high impedance 
loads; nominal 20 Hours at 20mA Drain. Batteries should be
removed when storing the unit >3 months.
Source current: 30mA Maximum
Sink current: 20mA Maximum
Output impedance: 2 Megohms
Specifications
Source resistance effect (Read mode): 0.1% error per 2000 Ohms
Overload protection: Protected to 120 Volts AC or DC
Overload indicator: Lamp indicates high current or misconnection
Short circuit duration: Continuous
Low voltage indicator: LO BAT arrow       turns on at 18 Volts
(approximately 10 operating hours remain)
Temperature effect: ±0.01%/°C (Based on 23°C ±23°C Recom-
mended Range)
Recommended temperature range: 32 to 122°F (0 to 50°C)
Operating temperature range: -5 to +140  °F (- 20 to + 60 °C)
Storage temperature range: -22 to +175°F (-30 to +80°C)
Relative humidity: 10 to 90%, non-condensing
Warm up time: 3 seconds to rated accuracy
Overall size: 21
/
2x 25
/
8x 51
/
8inches (63.5 x 66.7 x 130 mm)
Weight: 12.5 oz (0.35 kg)
AC Adaptors: optional; 120 or 240V, 50/60 Hz
Carrying case: optional, zippered with belt loop
Operating instructions
Calibrate voltage inputsDisconnect one or both input wires from the device to be check or
calibrated. Attach the red (+) lead of the Model 235 to the plus input
of the device to be calibrated, connect the black (-) lead to the
minus terminal. Select the desired range and turn the
SOURCE/OFF/READ mode selector switch to the SOURCE 
position. Actual voltage sent to the receiving device is shown on the
LCD.
Output voltage is continuously adjustable with the QUIK-CHEK
switch in the DIAL position. The source voltage can be set to any
exact value from 0 to 200mV, 0 to 20V or -25 to 125% of 1 to 5V. 
HI and LO values are user adjustable and can be instantly selected
by the QUIK-CHEK switch.
Measure voltage outputsPlace the leads of the MODEL 235 across the voltage signal to be
measured. Place the MODE Switch in the READ position and 
select the range to be measured. Choose the 100mV position for
signals from -199.9mV to +199.9mV. Signals from -19.99V to
+19.99V can be measured with the 10V range. 1 to 5V signals can
be displayed in units of 0 to 100% to monitor live process signals.
When measuring voltages from high impedance sources, the
source resistance effect is 0.1% per 2000 Ohms. All ranges are ful-
ly protected to 120V AC against misconnection.
CONTROLLER
(TYPICAL)
TRANSMITTER
4-20mA
ADDITIONAL
4-20 mA OR 1-5V
INSTRUMENTSALTEK
235
SOURCE
MODE RECORDER
COMPUTER
LOGGER
ETC,
1-5V DC250Ω
ALTEK
235
READ
MODEANALYZER
VOLTAGE
SOURCE
mV SOURCE
ALTEK
235
SOURCE
MODECOMPUTER
RECEIVER
LOGGER
TRANSMITTER
Check 1 to 5V inputs in live loopAny 1 to 5V device in a 4 to 20mA loop can be calibrated without
breaking the loop or turning off the signal current. Clip the red lead
to the positive input terminal and the black lead to the negative of
the device to be checked or calibrated. It is not necessary to 
disconnect any associated 250 Ohm resistor. Make certain that
changing the signal input will not disturb the process or cause 
unexpected alarms when checking on-line instruments.
It is important to remember the Model 235 drives only the device to
which it is connected. It has no effect on other devices in the 4 to
20mA loop.
Set the RANGE switch to the 1 to 5 Volt range and the MODE
switch to SOURCE. the LCD will display 0 to 100% corresponding
to the 1 to 5 Volts required by the device being calibrated. The
voltage is set to any exact value by the 10 turn dial. Adjust HI and
LO trimmers to desired values for fastest repetitive calibration
through the QUIK-CHEK switch.
Additionally, SINK MODE will clamp the selected value in the
100mV and 10V Ranges to the maximum sink current of 20mA. For 
example, receivers requiring 0.25 to 1.25V may be calibrated in the
10 Volt range. Connect the Model 235 across the 62.5 Ohm 
resistor and set the LO and HI QUIK-CHEKS for 0.25 and 1.25V.