The field uniformity (or homogeneity) of CPX-VF and CRX-VF stations is 0 at 10 mm diameter.5%, and 1% at 25 mm diameter。For those interested in looking at a plot of field uniformity, Lake Shore can provide a B-Z contour plot of the field percentage deviation at or 1 mm above the grounded sample rack in a CPX-VF or CRX-VF station。To access these diagrams, go to sales@bagmakerblog.com Contact sales staff。

For helium temperature operations, the residual gas inside the probe station will condense and freeze on the coldest surface, and under normal operating conditions, the sample station is usually the fastest cooling station in the cryogenic probe station。You can keep the sample stand at room temperature during station cooling to avoid sample contamination。This is an effective way to minimize sample condensation and is often required when measuring surface-sensitive samples, as well as any equipment where maintaining low contact resistance is critical。This is achieved by allowing the radiation shield to cool first in order to attract most of the residual gas to it rather than to the sample mounted on the sample bench。Specifically, the temperature controller, which is used to precisely regulate the sample table and radiation shield temperature, keeps the sample table warm while the rest of the refrigerator cools to the base temperature, at which point any residual gas in the chamber will condense on the 4 K shield table。

Lake Shore offers three different types of probes that can be distinguished based on the probe tip material。For delicate or softer contact materials, such as gold, beryllium copper (BeCu) probes are recommended。These are the softest probe tips available, providing traditionally the lowest contact resistance and the smallest amount of contact metallization deformation。Over time, BeCu materials form a semi-insulating layer, which reduces contact performance。The probe material can be used with standard DC/RF probes and continuously variable temperature (CVT) probes。 At the other extreme, for aluminum, refractory metals, and other material contacts that produce oxides, the standard ZN50 tungsten probe will best Pierce the hard oxide material layer to form electrical contact with the layer below and will not dull as quickly as the softer probe material。Because the spring component on the CVT probe reduces the pressure at the apex of the tip, tungsten CVT probes may have difficulty penetrating hard insulation and are therefore not recommended for oxidizing contacts (e.g. aluminum).。 The Pelini probe tip material available on Lake Shore's standard DC/RF probes is a good intermediate solution between beryllium copper and tungsten。Perini probes have lower contact resistance, but slightly stronger tip material (also the least reactive material and least likely to form resistive oxides, especially at high temperatures)。

To calibrate the probe and the dispersion and loss of the probe station and network analyzer wiring, most network analyzers support SOLT (Short Circuit Open Load Through) calibration。For probing measurements, the CS-5 on-wafer calibration substrate (available from Lake Shore) is used as the reference standard for calibration。The GSG probe should be flattened to the calibration substrate before performing calibration at a given sample station temperature。After calibrating the probe, the frequency-dependent S-parameter of the wafer level DUT can be determined。The SOLT calibration method is sufficient for most conventional microwave on-wafer detection applications below 20 GHz。However, for higher frequency measurements, other calibration methods may be required。Above 20 GHz, the SOLT method is extremely sensitive to consistent probe placement and contact pressure for accurate calibration。To achieve better S-parameter accuracy at higher frequencies, Lake Shore recommends TLR (through reflection) or LRRM (Line reflection-reflection matching) on-wafer calibration techniques to reduce the impact of probe placement errors。These calibrations can be performed using the WinCal software package in conjunction with Cascade Microtech's calibration substrate。However, LRRM calibration method is sensitive to the change of load standard.For low temperature measurements, the temperature-dependent load resistance should be measured and compensated in the calibration calculation。

This is a multi-step process。First, use the toolbox resistance measurement to find a 0 generated on the contact.1 伏和 0.Current between 01 volts。We think this is a useful range, but depending on the materials and contacts, you may have to move out of this range。We usually start with a milliampere current and then move up or down to find the starting voltage。For the sake of discussion, assume a current of 10 microamps。Then go to the measurement section and select Ohm check only。Set the maximum current to the value selected in the toolbox (10 microamps in this example) and the minimum。The current is 1/10 of the maximum current (in this case, 1 microampere)。Set the count to 5 and run the ohm check。If the correlation is zero.9999 or higher, then you're good to go。If the correlation coefficient is less than 0.9999, try to reduce the maximum。The current and minimum current are increased by a factor of 3 and the ohm check is repeated。The purpose of this is to eliminate self-heating, which can distort the linear ohm check。This is especially important if AC excitation options are used。Self-heating during AC field measurements may inject noise into the measurement。Sometimes, reducing the current used in AC field measurements can improve the signal-to-noise ratio of the measurement。

The effective region is the effective region of the Hall sensor's average magnetic field。For users trying to measure a magnetic field that represents a large magnetic field gradient, knowing where it is can be a problem。When conducting magnetic pole surface tests, it is also important to understand that the strength of the magnetic field near the surface can drop dramatically。In this case, a difference of just a few thousandths of an inch in the distance between the sensor's active area and the magnet's surface can cause the Gaussian meter reading to vary more than the allowed tolerance。

There may be a slight, very small delay, but we have not measured and specified it, nor do we know whether the delay remains constant across the various measurements (AC or DC)。If you observe a measurement delay, it may also be due to the stability time of the measurement signal。The entire measuring stage is AC coupled to eliminate DC offset。

We've seen this before, and resetting to factory defaults should fix the problem。 To reset the instrument to factory default Settings: 1. Click on the "Settings" menu (top left corner of the screen)。 2. Click System Settings。 3. Click Reset, then click Reset instrument Settings。 4. A confirmation message will appear。Click Reset to confirm the operation。 If you're still having problems, go to sales@bagmakerblog.com Contact us for further troubleshooting。

Can you first confirm that you are using a pulse discharge magnetizer to do this？It should be possible to do what you ask, and the first thing to do is to make a custom coil that is sensitive enough to produce the measurement results, but at the same time does not overload the instrument's input (pulse X # turn) when discharging。Can you wind the coil yourself？ The Type 480 has an absolute input limit of 100V, but we recommend keeping it at or below 60V。Once you have a coil that works properly to measure pulses, automation can be achieved with custom software。You need to write your own software that can communicate through GPIB。In addition to using standard and common programming languages, LabVIEW is one of your options。

Please let me know if the measurement is correct。Also, do you have different probes or gauss gauges that you can compare the measurement results with？ If there is any problem, it is most likely the probe。The Hall sensor is located at the tip and is very sensitive。Wear, impact, etc., can easily damage the sensor, leading to such unexpected measurements。What happens when you zero the probe？Whether you received the "Offset is greater than expected" error message at the end of the zeroing process？

The instrument ignores Spaces and commas when parsing CRVHDR commands。Therefore, even if the sensor does not have a serial number, you need to enter the term in the serial number field。Example commands that work reliably for sensors without serial numbers are CRVHDR 21,SENSOR21,NONE,4,325,1, where NONE is used as the serial number。

Many highly regarded manufacturers of more complex measuring devices, such as voltmeters, recommend that such instruments be recalibrated every six months。 Temperature sensors are complex components made up of wires, welds, electrical connections, dissimilar metallurgy, electronic packages, seals, etc., so drift may occur during calibration。Just like a voltmeter, whose components degrade or change over time and use, all the "components" of a temperature sensor may also change, especially where they are joined together at the material interface。The degradation of the sensor material system is not as obvious as the degradation of the voltmeter performance。

With germanium and Cernox RTDS, there is a common misconception that higher resistance equates to a "better sensor" if this is interpreted to mean that the sensor has better resolution or higher accuracy (i.e. less uncertainty).。It is important to understand that the concepts of resolution and accuracy are largely meaningless if applied only to temperature sensors。These concepts only become meaningful when discussed in the framework of electronic devices used to measure their resistance。Many of the subtleties of the instrument can affect low temperature measurements, including excitation modes and how the instrument switches between resistance ranges。Ultimately, the excitation level and resistance range determine the electronic resolution and accuracy, which in turn determines the temperature resolution and accuracy。Since higher resistance means higher sensitivity for a given NTC thermometer type, it is expected that a thermometer with higher resistance should yield better resolution and accuracy。But as explained more thoroughly in this application note, this is generally not the case。The "best" sensor in terms of temperature resolution and accuracy is somewhat random, as it depends on the range of resistance over which the instrument is forced to operate。Overall, low-resistance samples perform just as well as high-resistance samples, and the difference that occurs is usually less than twice that。

Make sure your multimeter has a rated measuring resistance of up to 10 megohm and follow the following test procedure: 1. Verification diodes (Part 1) Place the positive (+) lead of the multimeter on I+ or V+ and the negative (-) lead on V- or I。About 5 megohm should be measured at room temperature。 2. Verification diodes (Part 2) Place the negative (-) lead of the multimeter on I+ or V+ and the positive (+) lead on V- or I。You should measure "open circuit" (infinite resistance)。 3. Verify sensor leads: Measurement between the I and V leads - Measure the resistance between the I+ and V+ leads。You should measure the total resistance of the wire。 - Measure the resistance between the V- and I- leads。You should measure the total resistance of the wire。 4. Verify sensor leads: Isolation - Place one lead of the multimeter in I+ or V+ and the other lead in the system ground terminal。You should measure "open circuit" (infinite resistance)。 - Place one lead of the multimeter on I- or V- and the other lead on the system ground terminal。You should measure "open circuit" (infinite resistance)。

The decision whether to recalibrate the sensor depends on your internal processes and the requirements of the quality department。 As you say, diode sensors are very stable in the long run, however, many customers who use our sensors to perform controlled measurements for their customers send them back every year, while others never recalibrate them。 Our temperature sensors come with a 3-year warranty, so if some problem in the sensor construction or material causes a change in the sensor calibration, it will be recalibrated or replaced during the warranty period。

The expected transverse peak-to-peak vibration of the sample on SHI-4-2 is a few microns, and the vibration along the low temperature thermostat axis is tens of microns。 If you don't do anything at all to mitigate incoming vibrations beyond those generated by the cold head at the cryostat, you may see a worse situation than that。 The two easiest things to do are to connect the turbopump to the cryostat using a pumping line vibration isolator (a large aggravating pumping line interruption)，And do the same with the flexible pipe by sandbagging it (I like 3 bags - 1 bag) on the floor，The two lines are located on top of the trapped lines，These lines should have at least a 90° arch or bend between the bag and the cold head，So they don't get strained)，Or I've seen a weighted "stand" flexible tube that can be clipped similar to a pump isolator。 If this is done, the vibration of the sample stand will be as expected, but if there are other vibration-sensitive components on the optical workbench, the entire workbench will still move due to the cold head。

Yes, the hose should be disconnected when everything is at room temperature。Please note that the accessories used in these systems are Aeroquip accessories, which are zero dead volume, self-sealing accessories。When these parts are properly assembled or disconnected, there should be no helium loss。 If you have additional questions, or would like me to provide you with your cold head (and compressor) manual (which it sounds like you probably already have), please email me at sales@bagmakerblog.com。This shall include specific instructions for making and disassembling Aeroquip fittings。

It is currently not possible to turn this feature off, but I have let our engineers know to consider this in future firmware updates。Currently, the timer is set to 30 minutes and requires touching the display to bring it back on。

Yes, because the position of the sample will directly affect the detection efficiency, which in turn affects the accuracy of the torque value。If you do not place the sample in the detection center, the torque value will be incorrect。Your measurement is only qualitative rather than quantitative - that is, you see the shape, but you can't rely on the measured number。

Yes, because both the electromagnet power supply and the electromagnet itself need to be cooled to dissipate heat while working。The value of water flow is very important。Without cooling, you can't even make a limited range of measurements。