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 firstname.lastname@example.org
Is the calibration of Dataforth modules traceable to NIST standards?
Yes, calibration of Dataforth modules is traceable to NIST standards.
Can you explain what is the difference between the “Standard frequency range” and the “Extended frequency range” for the DSCA33 module?
The user does not have to do anything special; the module operates seamlessly over the full frequency range of 45Hz to 20kHz. We needed to split the full frequency range into two ranges so we could define and specify the different accuracy levels associated with each subrange.
If you look further down the DSCA33 Specifications under Accuracy, you will notice the Standard frequency range from 45Hz to 1kHz carries an additional +/-0.25% Reading error. This error is in addition to the +/-0.25% Span error at 50/60Hz. So the total accuracy error will be +/-0.25% Span + (+/-0.25% Reading) = +/-0.50%.
And the Extended frequency range from 1kHz to 20kHz carries an additional +/-0.75% Reading error. This error is in addition to the +/-0.25% Span error at 50/60Hz. So the total accuracy error will be +/-0.25% Span + (+/-0.75% Reading) = +/-1.00%.
Keywords/Phrases: DSCA RMS, DSCA True RMS, DSCA RMS input module, DSCA True RMS input module, DSCA33
Is there an extra charge for the extended frequency range to 20kHz for a DSCA33-01C?
There is no extra charge for the extended frequency range in the DSCA33. If you look in the DSCA33 Specifications under Accuracy, you will notice the extended frequency range carries an additional +/-0.75% of Reading error. This error is in addition to the +/-0.25% Span error at 50/60Hz. So the total accuracy error will be +/-0.25% + (+/-0.75%) = +/-1.00%.
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
For a half-wave rectified sine, Crest Factor = 2, in a DSCA33, which additional error spec do I apply; the one for Crest Factor 1 to 2 or 2 to 3?
The DSCA33 Crest Factor additional error is specified in several ranges of 1 to 2, 2 to 3, 3 to 4, and 4 to 5. For every whole number Crest Factor 2 and greater, choose the pair with the applicable whole number to the right. That whole number is included in the range or mathematically: <=. The whole number at the left of a range is excluded from the range or mathematically: >.
Keywords/Phrases: DSCA33, Crest Factor, DSCA33 and Crest Factor
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.
Is it possible to measure an AC voltage on top of a DC voltage signal with the DSCA33?
The DSCA33 is AC coupled, so it will reject the DC portion of the signal and only measure the AC portion. As long as the signal is within the protection specifications of the module (these can vary depending on the specific model of DSCA33) there will be no issue measuring VAC on top of VDC.
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.
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.
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
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.
What is the input impedance of the DSCA33 module?
For models DSCA33-01 through DSCA33-05, the input impedance is 499kOhm with a <100pF capacitor in parallel with the resistor. For the DSCA33-06 and DSCA33-07, the input impedance is 100 milliohms and 25 milliohms respectively.
How will the DSCA33 behave with an input signal that is non-sinusoidal, with a quick current spike and zero current for the rest of the waveform?
The DSCA33 would still output the RMS of the waveform. However, the DSCA33 may be less accurate due to the crest factor of such a signal.
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 size wires do the DSCA modules accept?
DSCA module screw terminals are rated to wire gage AWG: 28 – 12.
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.
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.
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