- FAQ (Frequently Asked Questions)
FAQ (Frequently Asked Questions)
Our shipping instructions for repair and calibration are as follows:
- Ship directly to Metrolab with all freight charges prepaid. Goods will be shipped back to your office with collect charges.
- After first tests, we will send you a formal quotation for the calibration.
- Your Purchase Order and prepayment will signal your approval of the quotation and shipping instructions.
Probably. As much as we'd like to sell you one of our spiffy new instruments, we will repair and/or calibrate our beloved veterans as long as we can get parts. Please contact us for a quote.
We very much appreciate the confidence implicit in this question, but the answer is no. Every magnetometer is different, and our procedures and equipment are only set up to handle our own instruments.
Yes, you can – and probably other programming environments as well. Please see this Technical Note
Bad news: there is none. Having said that, we may be able to help you out with an undocumented, unsupported and unpretty LabVIEW driver that we use internally. Please contact us.
Here are the things you should check, in order:
- The micro-switches should be set to 000100100, the baud rate to 2400 (center jumper on the 14-pin header) and no flow control (= “no handshake”, right-hand jumper on the two four-pin headers).
- The stickiest problem is often the RS232 cable. Pin-out specifications for both DB-9 and DB-25 connectors are in Section 6.2 of the the PT2025 manual, "Connecting the RS 232 C Interface." If you’re not using flow control, as suggested above, the only relevant pins are 2 and 3: pin 2 on the DB-9 should be connected to pin 2 on the DB-25, and likewise pin 3 -> pin 3. Please take the time to check your cable.
- Use a terminal emulator such as TerraTerm to test basic communication. A few simple commands for initial tests are:
Ctrl+E : should return the displayed field value
S1, S2, S3 or S4 : should return the various status registers
R : lights the “REM/SEARCH” light (In REMOTE mode)
D0 and D1 : should toggle the display from MHz to Tesla and back
Commands do not need to be followed by a line terminator like carriage-return; they do need to be upper case.
Probably because you did not purchase the IEEE-488 option. All PT2025s have the GPIB connector; what's missing are the interface chips, because they are becoming rare. We can, however, easily retrofit your instrument; please contact us for an offer.
Probably because the ampule containing the heavy-water NMR sample is broken. Probe ranges 1-5 use robust rubber (hydrogen, or proton) samples, but ranges 6-8 use a glass ampule with heavy water (deuterium). This ampule can break if subjected to shock or freezing. Please contact us for a repair offer.
Probably because you have selected the incorrect field polarity. After finding the NMR signal, the PT2025 starts regulating the frequency to precisely track the NMR signal. This regulation diverges if the field polarity is incorrect. After a few such failures, the PT2025 tries switching the field polarity on its own, but this trial-and-error process takes time. Try switching the field polarity, and the instrument should lock onto the signal immediately.
Technically, it's not drifting, it's tracking. After the signal is found, the PT2025 tracker gradually centers the NMR signal on the modulation sweep. If the "Fine" adjustment (vernier dial knob on the front panel) is not in the middle of its range, the NMR pulse will initially be off-center, and will need to be corrected. The correction takes a few seconds, and during that time, it looks like the measurement is drifting. To avoid this, set the "Fine" ajustement to 5 before launching a search.
THM1176 / TFM1186
The THM1176 has to be returned to the factory for recalibration. The procedure for returning your instrument is as described above, in the section "General." For the sake of cost efficiency, we calibrate the THM1176 in batches, four times a year; please see the THM1176 manual or the price list for the dates. You can have your instrument calibrated outside these times, but the price is higher – please see the price list for details.
Yes, but you may have to configure Windows to install an older version of Microsoft's .NET Framework. Please see this Technical Note
We have a Technical Note
that details how to configure the THM1176 software for the most common usage scenarios. Please check this note, and if you still cannot figure out how to perform your measurement, please do not hesitate to contact us.
We have a Technical Note
that details the most common problems encountered with the THM1176, TFM1186, THM1176 software, and THM1176-PDA. Please consult this note, and if it does not cover your problem, please do not hesitate to contact us.
Because the computation of B-magnitude rectifies the signal, thus doubling the frequency. If you want the "true" rotation frequency of the B-vector, you need to look at the spectrum of the field components. The THM1176 software allows you to do just that.
Officially no, but unofficially, we have some unsupported code that should get you started. Please see this Technical Note
Are you using an MFC3045 with the optional built-in USB interface ("MFC3045-USB"), or are you using a USB-to-RS232 adapter? If so, you may well be experiencing a common timing problem. Please set the “Wr/Rd delay” in the WinMFC-9 software to 400ms. This option is available from the “Options” - “Serial Port” menu.
Changing the gain changes the input impedance, which changes the input bandwidth. Depending on your coil impedance and signal spectrum, this can significantly change your results. Please see Section 5-3 of the FDI User's Manual, "Input Adaptation".
Good question! Yes. You can either short-circuit your coil (IN+ to IN-), or you can ground them, which will short-circuit them internally.
A common cause is that the battery that maintains the date/time of the crate controller (the embedded Windows PC) is depleted. When the date/time is invalid, the boot process hangs with a BIOS prompt. Attach a keyboard and monitor to the crate controller to verify that this is the problem. If so, replace the battery (type CR2032), reset the date/time, and continue booting. If all is well, you can disconnect the keyboard and monitor and boot normally.
The PM1055 was originally designed for our PT2025 NMR Precision Teslameter, so the field gradients must be less than about 1400 ppm/cm – otherwise the PT2025 would not be able to measure (see Section "Magnetic Environment" in Section 2.2 of the PT2025 manual
). In reality, the gradients are much lower; for example, the field map of PM1055 S/N 008
shows gradients at the center of less than 140 ppm/cm. Generally, remember that the PM1055 is intended to be used as a reference magnet, not for NMR spectroscopy or MR imaging.
As explained on the web page
, the PM1055 contains an auxiliary coil to be able to offset temperature drift, or otherwise modulate the field. The Lemo connector connects to that coil.