DSCA38: Strain Gage Input Signal Conditioners. Dataforth

Specialists in data acquisition, signal conditioning and data communication

English

Each DSCA38 strain gage input module provides a single channel of strain gage input which is filtered, isolated, amplified, and converted to a high-level voltage output. Signal filtering is accomplished with a five-pole filter which is optimized for step response. An anti-aliasing pole is located on the field side of the isolation barrier, and the other four poles are on the system side. After the initial field-side filtering, the input signal is chopped by a proprietary chopper circuit. Isolation is provided by transformer coupling, again using a proprietary technique to suppress transmission of common mode spikes or surges.

The DSCA38 can interface to transducers with a nominal resistance of 100 Ohm to 10 kOhm. Strain gage excitation is provided from the module by a stable 10V or 3.333V source. This source is fully isolated, allowing the amplifier inputs to operate over the full range of the excitation voltage. This feature enables the module to be interfaced to other sensors requiring exctitation.

Module output is either voltage or current. For current output models a dedicated loop supply is provided at terminal 3 (+OUT) with loop return located at terminal 4 (-OUT). The system-side load may be either floating or grounded.

Special input circuits provide signal input and excitation protection against accidental connection of power-line voltages up to 240VAC and against transient events as defined by ANSI/IEEE C37.90.1. Protection circuits are also present on the signal output and power input terminals to guard against transient events and power reversal. Signal and power lines are secured to the module using screw terminals which are in pluggable terminal blocks for ease of system assembly and reconfiguration.

The modules have excellent stability over time and do not require recalibration, however, zero and span settings are adjustable up to ±5% to accommodate situations where fine-tuning is desired. The zero adjustment can be used to offset bridge imbalances. The adjustments are made using potentiometers located under the front panel label and are non-interactive for ease of use.

Interfaces to 100 Ohm through 10 kOhm Strain Gages
Industry Standard Output of either ±10V, 0-20mA, or 4-20mA
1500Vrms Transformer Isolation
ANSI/IEEE C37.90.1 Transient Protection
Input Protected to 240VAC Continuous
True 3-Way Isolation
Wide Range of Supply Voltage
100dB CMR
Fully Isolated Excitation Supply
±0.03% Accuracy
±0.01% Linearity
Easily Mounts on Standard DIN Rail
C-UL-US Listed
CE and ATEX Compliant

DSCA38 Devices

Part Number	Excitation Voltage	Sensitivity	Input Configuration	Input Range	Output Range	Bandwidth	Mechanical Format
DSCA38-01 Order Now	3.333 V	3 mV/V	Full Bridge	-10 to +10 mV	-10 to +10 V	3 kHz	DIN rail
DSCA38-02 Order Now	10.0 V	3 mV/V	Full Bridge	-30 to +30 mV	-10 to +10 V	3 kHz	DIN rail
DSCA38-03 Order Now	3.333 V	3 mV/V	Half Bridge	-10 to +10 mV	-10 to +10 V	3 kHz	DIN rail
DSCA38-04 Order Now	10.0 V	3 mV/V	Half Bridge	-30 to +30 mV	-10 to +10 V	3 kHz	DIN rail
DSCA38-05 Order Now	10.0 V	2 mV/V	Full Bridge	-20 to +20 mV	-10 to +10 V	3 kHz	DIN rail
DSCA38-06 Order Now	3.333 V	10 mV/V	Full Bridge	-33.3 to +33.3 mV	-10 to +10 V	3 kHz	DIN rail
DSCA38-07 Order Now	10.0 V	10 mV/V	Full Bridge	-100 to +100 mV	-10 to +10 V	3 kHz	DIN rail
DSCA38-08 Order Now	3.333 V	3 mV/V	Full Bridge	-10 to +10 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-08C Order Now	3.333 V	3 mV/V	Full Bridge	-10 to +10 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-08E Order Now	3.333 V	3 mV/V	Full Bridge	-10 to +10 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-09 Order Now	10.0 V	3 mV/V	Full Bridge	-30 to +30 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-09C Order Now	10.0 V	3 mV/V	Full Bridge	-30 to +30 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-09E Order Now	10.0 V	3 mV/V	Full Bridge	-30 to +30 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-10 Order Now	10.0 V	3 mV/V	Half Bridge	-10 to +10 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-10C Order Now	10.0 V	3 mV/V	Half Bridge	-10 to +10 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-10E Order Now	10.0 V	3 mV/V	Half Bridge	-10 to +10 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-11 Order Now	10.0 V	3 mV/V	Half Bridge	-30 to +30 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-11C Order Now	10.0 V	3 mV/V	Half Bridge	-30 to +30 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-11E Order Now	10.0 V	3 mV/V	Half Bridge	-30 to +30 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-12 Order Now	10.0 V	2 mV/V	Full Bridge	-20 to +20 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-12C Order Now	10.0 V	2 mV/V	Full Bridge	-20 to +20 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-12E Order Now	10.0 V	2 mV/V	Full Bridge	-20 to +20 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-13 Order Now	3.333 V	10 mV/V	Full Bridge	-33.3 to +33.3 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-13C Order Now	3.333 V	10 mV/V	Full Bridge	-33.3 to +33.3 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-13E Order Now	3.333 V	10 mV/V	Full Bridge	-33.3 to +33.3 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-14 Order Now	10.0 V	10 mV/V	Full Bridge	-100 to +100 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-14C Order Now	10.0 V	10 mV/V	Full Bridge	-100 to +100 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-14E Order Now	10.0 V	10 mV/V	Full Bridge	-100 to +100 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-15 Order Now	3.333 V	3 mV/V	Full Bridge	0 to +10 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-15C Order Now	3.333 V	3 mV/V	Full Bridge	0 to +10 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-15E Order Now	3.333 V	3 mV/V	Full Bridge	0 to +10 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-16 Order Now	10.0 V	3 mV/V	Full Bridge	0 to +30 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-16C Order Now	10.0 V	3 mV/V	Full Bridge	0 to +30 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-16E Order Now	10.0 V	3 mV/V	Full Bridge	0 to +30 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-17 Order Now	3.333 V	3 mV/V	Half Bridge	0 to +10 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-17C Order Now	3.333 V	3 mV/V	Half Bridge	0 to +10 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-17E Order Now	3.333 V	3 mV/V	Half Bridge	0 to +10 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-18 Order Now	10.0 V	3 mV/V	Half Bridge	0 to +30 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-18C Order Now	10.0 V	3 mV/V	Half Bridge	0 to +30 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-18E Order Now	10.0 V	3 mV/V	Half Bridge	0 to +30 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-19 Order Now	10.0 V	2 mV/V	Full Bridge	0 to +20 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-19C Order Now	10.0 V	2 mV/V	Full Bridge	0 to +20 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-19E Order Now	10.0 V	2 mV/V	Full Bridge	0 to +20 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-20 Order Now	3.333 V	10 mV/V	Full Bridge	0 to +33.3 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-20C Order Now	3.333 V	10 mV/V	Full Bridge	0 to +33.3 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-20E Order Now	3.333 V	10 mV/V	Full Bridge	0 to +33.3 mV	0 to 20 mA	3 kHz	DIN rail
DSCA38-21 Order Now	10.0 V	10 mV/V	Full Bridge	0 to +100 mV	0 to +10 V	3 kHz	DIN rail
DSCA38-21C Order Now	10.0 V	10 mV/V	Full Bridge	0 to +100 mV	4 to 20 mA	3 kHz	DIN rail
DSCA38-21E Order Now	10.0 V	10 mV/V	Full Bridge	0 to +100 mV	0 to 20 mA	3 kHz	DIN rail

Frequently Asked Questions

Can Dataforth provide calibration reports for modules I purchased?

Yes we can provide calibration reports for the modules that you purchased.

You can either
a) visit https://www.dataforth.com/TestDataReport.aspx to search for Test Report Datasheets by Serial Number or
b) you can send us a list of model numbers and their serial numbers to support@dataforth.com

Is the calibration of Dataforth modules traceable to NIST standards?

Yes, calibration of Dataforth modules is traceable to NIST standards.

What does “sensitivity” mean on my strain gage input module?

The sensitivity is listed on the datasheet to help determine what strain gages/load cells will be compatible with that module. Strain gages do not have a specific voltage output range (i.e. -30mV to 30mV) but rather a voltage output range that varies depending on the excitation voltage applied to the strain gage (its "sensitivity"). Since our strain gage modules have a fixed voltage input range and a fixed excitation voltage, the sensitivity is the most reliable way to determine if a strain gage is compatible with our module.

For example, a load cell with a 3mV/V sensitivity will output 30mV at full scale with a 10V excitation voltage, because 3mV/V * 10 V = 30mV. A signal conditioner with a 10V excitation and a -30mV to 30mV input range will be compatible with a load cell of 3mV/V sensitivity.

ATEX conformity: Is it possible to use the DSCA38-12C in zone IIC (hydrogen)?

The DSCA38-12C conforms to EN60079-15 2005.

For use in:
ATEX 94/9/EC
Group II
Category 3 (Zone 2)

Does Dataforth have any DSCA modules that can operate on a 12Vdc power supply?

Dataforth does not have any custom modules that run on 12VDC power. Most DSCA modules require a minimum power supply voltage of 15VDC while some require a minimum of 19VDC. Both are suitable for use with nominal 24VDC power supplies over the full operating temperature range of -40C to +85C. Dataforth offers a line of accessory power supplies, PWR-PS5RxW, which have been qualified for use with the DSCA product line. https://www.dataforth.com/catalog/pdf/PWR-PS5RxW.pdf

What does "Response time, 90% span" mean on the datasheet for my module?

Normally, a response time figure refers to how quickly a module's output can "respond" to a change in the input signal. "Response time, 90% span" refers to how fast a module can adjust its output when a step signal is applied at the input, where the magnitude of this step input is 90% of the input span of the module.

Where can I find the MTBF of my module?

Information on MTBF for SCM5B, SCM7B, 8B and DSCA is available on our website. Please see application note AN802 for more details. Application notes can be found under the "Literature" tab on the top navigation bar.

How does the load resistance of a module affect the noise at the output?

Noise at the output of a module is independent of load resistance.

How do I convert an RMS voltage to its corresponding peak voltage?

To convert an RMS voltage to its corresponding peak voltage, you simply take the RMS voltage value and multiply it by the square root of 2, or roughly 1.414.

For example, 1500Vrms corresponds to a peak voltage of 1500 * 1.414 = 2121 Vp

Does Dataforth offer any DSCA38 modules with a 10Hz bandwidth?

None of the standard DSCA38 products have a 10Hz bandwidth. However, we do offer some custom products that have 10Hz bandwidth, such as the DSCA38-1348 or the DSCA-1455. Dataforth can also design a custom product with 10Hz bandwidth, as long as the required specifications are reviewed and approved by our Engineering department. Please contact our support team if you are interested in a custom product or have any questions.

If the input range of my signal conditioner is -1V to +1V and the output range is 0 to 10V, does this mean that it ignores polarity?

A signal conditioner with these I/O ranges does not mean that the module ignores the polarity of your voltage input. The output of voltage input modules are scaled linearly, meaning an input of -1V would correspond to an output of 0V, an input of 0V would correspond to an output of 5V, an input of +1V would correspond to an output of 10V, and so on.

Do DSCA modules come with screw terminal blocks installed?

Yes, DSCA modules do come with the screw terminal blocks installed. The screw terminal accessories listed in our catalog are intended as replacements in case a terminal block is damaged or lost.

What does it mean when an input module has for example a 3kHz bandwidth?

A 3kHz bandwidth on an input module means it can accept voltages from DC to 3000Hz. Any frequency higher than that and the signal will start to be attenuated by the filter at the input.

Is the DSCA38-02 compatible with a load cell with a sensitivity of 2mV/V? How would it affect measurements?

For the DSCA38-02, the +/-30mV range maps to the +/-10V output; -30mV input = -10V output and +30mV input = +10V output. The sensitivity is a specification that refers to the sensitivity of the strain gauges that are fully compatible with the module.

If a DSCA38-02 is used with a load cell that has 2mV/V sensitivity, then the module's output is limited to two thirds of the full range (i.e. +/-20mV). This assumes the load cell has a rated excitation voltage of 10V. This reduced output range might be okay depending on the specific use case.

What is the output resolution of the DSCA series?

The DSCA series is completely analog, so the output resolution cannot be expressed in terms of bits as it is not a digital signal. The only thing that would cause any uncertainty/lack of clarity in your output signal would be the output ripple and noise, which is rated at a typical value of 0.025% span RMS as listed in the datasheet.

Can Dataforth analog modules be used in high vibration environments? If so, what type of testing or certification was completed?

SCM5B, SCM7B, 8B SensorLex, and DSCA modules are well suited for use in high vibration environments. These modules and their associated accessories have undergone testing for random vibration, shock, and swept sine wave vibration. Details of each of these testing methods are provided below:

Random Vibration (Operating):
○ MIL-STD 202G, Method 214A, Condition 1
- Frequency Range: 50-2000Hz, flat spectrum
- Vibration Intensity: 7.56 Grms
- Duration: 10min/axis (X, Y, Z)

Shock (Operating):
○ MIL-STD-810F, Method 516.5
- Pulse Shape: Sawtooth
- Test Level: 30G
- Duration 11ms
- Orientation: +/-X, +/-Y, +/-Z

Swept Sine Vibration (Operating)
○ MIL-STD-810G, Method 514.6, modified
- Frequency Range: 10-2000Hz
- Vibration Intensity: 5Gp-p
- Sweep Rate: 1 octave/min
- Orientation: X, Y, Z

Declaration of conformity for the above-listed tests can be provided upon customer request. Please contact customer service if a copy of the declaration is needed.

What size wires do the DSCA modules accept?

DSCA module screw terminals are rated to wire gage AWG: 28 – 12.

Due to resource constraints on my computer, I'm unable to open the three dimensional CAD models provided on your website. Does Dataforth provide two demensional CAD models for download as well?

Two dimensional CAD models can be generated upon customer request. Please contact Customer Service for assistance.

Is a completion resistor required for a DSCA38 in a half-bridge configuration? If so, does the resistor come with the module?

A completion resistor is not required for a DSCA38 strain gauge module in a half-bridge configuration. Half-bridge configuration using the DSCA38 requires two active strain gauges which are denoted as Rg in the block diagrams of the module's datasheet.

A quarter-bridge arrangement uses only one active strain gauge and connects to the customer supplied resistor which is denoted as R3 in the quarter-bridge block diagram of the DSCA38's datasheet. This completion resistor is not provided since the resistance value needed will vary depending on the resistance of active strain gauge being used. When using the DSCA38 in a quarter-bridge arrangement, the resistance of R3 should match Rg. Further balancing of the bridge might be needed to offset any small differences between the resistance values of R3 and Rg.

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Model Number	Input Units	Input Range	Output Units	Output Range	Bandwidth	Sensor Type	Status*	Comments
DSCA38-1335 Request Quote	mV	-21mV TO +21mV	V	-10V TO +10V	8KHZ	STRAIN GAGE	PR	7Vexc., Full Bridge, 3mV/V
DSCA38-1337 Request Quote	mV	0mV TO +250mV	V	0V TO +10V	1KHZ	STRAIN GAGE	QU	5V @ 50mA exc.
DSCA38-1338 Request Quote	mV	0mV TO +10mV	V	0V TO +10V	1KHZ	STRAIN GAGE	QU	5V @ 50mA exc.
DSCA38-1348 Request Quote	mV	-20mV TO +20mV	V	-10V TO +10V	10HZ	STRAIN GAGE	PR	10V excitation
DSCA38-1363 Request Quote	mV	-10mV TO +10mV	V	-10V TO +10V	3HZ	STRAIN GAGE	PR	5V EXC., 2mV/V SENSITIVITY
DSCA38-1376 Request Quote	mV	-10mV TO +10mV	V	-10V TO +10V	250Hz	STRAIN GAGE	PR	10V Exc., 1mV/V Sensitivity
DSCA38-1377 Request Quote	mV	-10mV TO +10mV	V	-10V TO +10V	3Hz	STRAIN GAGE	PR	3.333V Exc., 3mV/V Sensitivity
DSCA38-1389 Request Quote	mV	-30mV TO +30mV	V	-10V TO +10V	3kHz	STRAIN GAGE	QU	Same as DSCA38-02 with 25% gain adjustment
DSCA38-1408 Request Quote	mV	-10mV TO +10mV	mA	+4mA TO +20mA	3Hz	STRAIN GAGE	PR	Similar to DSCA38-08C
DSCA38-1422 Request Quote	mV	-30mV TO +30mV	V	-10V TO +10V	8kHz	STRAIN GAGE	PR	10V Exc, 3mV/V Sensitivity, 25% Gain Adjustment
DSCA38-1455 Request Quote	mV	0mV TO +2.34mV	V	0V TO +5V	10HZ	STRAIN GAGE	PR	10V Exc., 0.234mV/V Sensitivity
DSCA38-1468 Request Quote	mV	0mV TO +20mV	V	-10V TO +10V	3kHz	STRAIN GAGE	PR	10V Exc., 2mV/V Sensitivity
DSCA38-1489 Request Quote	mV	0mV TO +50mV	V	0V TO +10V	3kHz	STRAIN GAGE	QU	10V Exc., 5mV/V Sensitivity
DSCA38-1496 Request Quote	mV	-500mV TO +500mV	V	-5V TO +5V	100Hz	STRAIN GAGE	PR	4-pole butterworth filter
DSCA38-1518 Request Quote	mV	0mV TO +9.6mV	V	0V TO +10V	3kHz	STRAIN GAGE	PT	6V Exc., 1.6mV/V Sensitivity
DSCA38-1519 Request Quote	mV	0mV TO +33.3mV	V	0V TO +10V	3kHz	STRAIN GAGE	PT	10V Exc., 3.33mV/V Sensitivity
DSCA38-1544 Request Quote	mV	-20mV TO +20mV	V	-10V TO +10V	250HZ	STRAIN GAGE	PR	10V Exc., 2mV/V Sensitivity
DSCA38-1611 Request Quote	mV	0mV TO +100mV	V	0V TO +10V	3kHz	STRAIN GAGE	PR	5V Exc., 20mV/V Sensitivity
DSCA38-1636 Request Quote	mV	-100mV TO +100mV	V	-10V TO +10V	8kHz	STRAIN GAGE	PR	10V Exc, 10mV/V Sensitivity, 25% Gain Adjustment
DSCA38-1683 Request Quote	mV	-75mV TO +75mV	V	-10V TO +10V	8kHz	STRAIN GAGE	PR	10V Exc, 7.5mV/V Sensitivity, 25% Gain Adjustment
DSCA38-1762 Request Quote	mV	-10mV TO +10mV	V	-10V TO +10V	3kHz	STRAIN GAGE	PR	7V Exc., Full Bridge, 1.43mV/V sensitivity
DSCA38-1793 Request Quote	mV	-20mV TO +20mV	V	-10V TO +10V	1kHz	STRAIN GAGE	PR	5V Exc., Full Bridge, 4mV/V sensitivity
DSCA38-1896 Request Quote	mV	0mV TO +10mV	mA	+4mA TO +20mA	3Hz	STRAIN GAGE	QU	10V Exc., 1mV/V Sensitivity
DSCA38-1907 Request Quote	mV	0mV TO +16mV	V	0V TO +10V	3kHz	STRAIN GAGE	PR	5V Exc., 3.2mV/V Sensitivity

* ... Status Codes: PR = Production, PT = Prototypes, QU = Quoted

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