JPS63259448A - Magnet temperature controller for magnetic nuclear resonator - Google Patents
Magnet temperature controller for magnetic nuclear resonatorInfo
- Publication number
- JPS63259448A JPS63259448A JP62093059A JP9305987A JPS63259448A JP S63259448 A JPS63259448 A JP S63259448A JP 62093059 A JP62093059 A JP 62093059A JP 9305987 A JP9305987 A JP 9305987A JP S63259448 A JPS63259448 A JP S63259448A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- magnet
- voltage
- temperature
- control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005481 NMR spectroscopy Methods 0.000 claims description 9
- 239000000463 material Substances 0.000 claims 1
- 239000002904 solvent Substances 0.000 claims 1
- 230000003247 decreasing effect Effects 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
Landscapes
- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は核磁気共鳴装置に係り、特に小型の永久磁石の
温度ドリフトを補正し安定な磁場を得るのに好適な、温
度制御回路に関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a nuclear magnetic resonance apparatus, and particularly to a temperature control circuit suitable for correcting temperature drift of a small permanent magnet and obtaining a stable magnetic field. It is.
従来の装置は、特許５３７２２６号に記載のように、磁
場ドリフトに対する制御は、ＮＭＲの分散信号から得た
磁場ドリフトを分を、電圧で得て磁石のフィードバック
コイルに帰環して、磁場ドリフトを補正していた。In the conventional device, as described in Japanese Patent No. 537226, magnetic field drift is controlled by obtaining the magnetic field drift obtained from the NMR dispersion signal as a voltage and returning it to the feedback coil of the magnet. I was correcting it.
上記の従来技術では、磁石温度を一定に保つためのセン
サーが、磁石と磁石周辺に設けられたす−ミスタで構成
され、磁石外部の温度変化を感知するには相当の時定数
があり、復帰する迄に長時間を要する。磁場がドリフト
している間、磁場制御回路のＮＭＲロックオンを動作さ
せて測定することが可能であるが、ロックオンが外れ易
い。また磁石が鉄金属の塊りであり、サーミスタだけで
はレスポンス良く磁石温度を検出することは不可能で、
大幅な磁石外部の温度変化にレスポンス良く対応する配
慮がされておらず、磁場ドリフトの大きい時ロックオン
が外れ易いので長時間の連続測定が不可能である問題が
あった。In the above conventional technology, the sensor for keeping the magnet temperature constant consists of a magnet and a mister installed around the magnet, and it takes a considerable time constant to detect temperature changes outside the magnet. It takes a long time to do so. While the magnetic field is drifting, it is possible to perform measurements by operating the NMR lock-on of the magnetic field control circuit, but the lock-on is likely to be lost. Also, since the magnet is a block of iron metal, it is impossible to detect the magnet temperature with a good response using only a thermistor.
There was a problem that no consideration was given to respond well to large temperature changes outside the magnet, and that lock-on was easily released when the magnetic field drift was large, making continuous measurement over a long period of time impossible.
本発明の目的は、上記の問題を解決して、現行の厳しい
室温条件の制約を大幅に解除して、常に安定した磁場を
得ることである。The purpose of the present invention is to solve the above problems, to significantly remove the current strict constraints of room temperature conditions, and to obtain a constantly stable magnetic field.
ｃ問題点を解決するための手段〕
ＮＭＲのロックオン信号は１分散波形を用いるので極性
が容易に得やすく制御信号として、磁場ドリフトを補正
するのに最適でレスポンスが良い。Means for Solving Problem c] Since the NMR lock-on signal uses a unidispersion waveform, the polarity can be easily obtained, and it is suitable as a control signal for correcting magnetic field drift and has a good response.
一方温度センサーのサーミスタは、レスポンスが遅く磁
石の正確な温度検出に時間がかかり、磁場ドリフトと磁
石温度制御に相関がないため安定するのに長時間を必要
とするので、レスポンスの良いＮＭＲロック信号の一部
を磁石温度制御１回路に一制御信号として、アンプを介
して供給することで間者の相関が取れることにより、上
記目的を達成することが出来る。On the other hand, the thermistor of the temperature sensor has a slow response and takes time to accurately detect the temperature of the magnet, and there is no correlation between magnetic field drift and magnet temperature control, so it takes a long time to stabilize. The above object can be achieved by supplying a part of the signal to one magnet temperature control circuit as one control signal through an amplifier, so that a correlation can be established between the signals.
リミッタ回路によりある一定量以上の磁場ドリフトがあ
った時のみ、制御アンプに温度制御信号が出力されるよ
う動作するので、温度制御アンプは、その磁場ドリフト
により発生した電圧と温度センサーからの出力電圧との
和が、磁石温度制御信号としてヒータの制御トランジス
タを動作させヒータ電流を制御する。これにより磁場ド
リフトが高磁場の時、磁石温度は設定値より低いので、
ンサの出力電圧■ΔＥ１に印加され、従来の制御電流よ
り多く流れるようになっている。また磁場ドリフトが低
磁場の時はその逆となるよう動作し、従来の制御電流よ
り少なく流れるようになっている。さらに磁場が安定し
ている時はスイッチにより切り離しておけるし、ＬＯＣ
Ｋ ＯＮ又はＯＦＦの時も自動的に切り離されるので誤
動作することはない。The limiter circuit operates so that a temperature control signal is output to the control amplifier only when there is a magnetic field drift of a certain amount or more, so the temperature control amplifier outputs the voltage generated by the magnetic field drift and the output voltage from the temperature sensor. The sum of the values is used as a magnet temperature control signal to operate the heater control transistor and control the heater current. As a result, when the magnetic field drift is high, the magnet temperature is lower than the set value, so
The control current is applied to the output voltage ■ΔE1 of the sensor, and flows in a larger amount than the conventional control current. Also, when the magnetic field drift is low, the operation is reversed, and less current flows than the conventional control current. Furthermore, when the magnetic field is stable, it can be disconnected with a switch, and the LOC
Since it is automatically disconnected even when K is ON or OFF, there will be no malfunction.
以下、本発明の実施例を第１図により説明する。 Embodiments of the present invention will be described below with reference to FIG.
ＮＭＲロック信号は、第２図の如く磁場のドリフトΔＢ
１に相当する電圧ΔＥ１が磁場制御回路４で増幅され、
磁石のポール間にＩＩしたフィードバックコイル５に供
給され、一定の磁場を保つよう構成されている。′磁場
制御回路４の互に極性の対抗するＰＮＰ及びＮＰＮトラ
ンジスタのエミッタより得た信号は、スイッチ６を介し
てダイオードで構成したリミッタ回路７に供給されて、
ドリフト電圧ΔＥ１がある一定値を越えた時だけ制御ア
ンプ８にΔＥ１の出力電圧が発生する。この電圧と磁石
温度センサ１ｏからの電圧とが、差動型加算器１１に入
力され、その和の電圧が温度制御アンプ１２で増幅し、
磁石温度制御ヒータ１３を制御して、ドリフトしている
分量のみ平常時に制御している時より、余計にヒータ電
流を増したり減したりして該磁石ヒータに供給する。The NMR lock signal is generated by the magnetic field drift ΔB as shown in Figure 2.
The voltage ΔE1 corresponding to 1 is amplified by the magnetic field control circuit 4,
It is supplied to a feedback coil 5 placed between the poles of the magnet, and is configured to maintain a constant magnetic field. 'The signals obtained from the emitters of the PNP and NPN transistors of opposite polarity in the magnetic field control circuit 4 are supplied via the switch 6 to the limiter circuit 7 constituted by a diode.
An output voltage of ΔE1 is generated in the control amplifier 8 only when the drift voltage ΔE1 exceeds a certain certain value. This voltage and the voltage from the magnet temperature sensor 1o are input to the differential adder 11, and the sum voltage is amplified by the temperature control amplifier 12.
The magnet temperature control heater 13 is controlled to supply the heater current to the magnet heater by increasing or decreasing the heater current more than when controlling only the drifting amount in normal times.
本実施例によれば、磁場ドリフトが平常時より大きく磁
場ロックが外れ易・い時、磁場ドリフトに相応したヒー
タ電流を補正出来るので、磁場ロックが外れに＜＜、ま
たすばやく磁石温度を平常時の制御状態に復帰出来る効
果がある。According to this embodiment, when the magnetic field drift is larger than normal and the magnetic field lock is easily released, the heater current can be corrected in accordance with the magnetic field drift, so that the magnetic field lock is released and the magnet temperature is quickly adjusted to the normal state. This has the effect of returning to the controlled state.
〔発明の効果３
磁場ドリフトは室温の温度変化が仕様値より大きいため
で、従来メーカでは室温の変動幅をかなり厳しく設定し
ているため、室温コントロールの設備に出費を余儀なく
されている。本発明によれば、室温設定の範囲を大幅に
緩和して、広い室温設定範囲を得ることが出来るので、
余分な空調工事等による出費を必要としない、また電力
消費も減るので経済的な効果がある。[Effect of the invention 3] Magnetic field drift is caused by a temperature change in the room temperature that is larger than the specified value, and conventional manufacturers have set the room temperature fluctuation range quite strictly, forcing them to spend money on room temperature control equipment. According to the present invention, the room temperature setting range can be significantly relaxed and a wide room temperature setting range can be obtained.
There is no need for extra expenses for air conditioning work, etc., and power consumption is also reduced, so there is an economical effect.
第１図は本発明の実施例を示す図、第２図はＮＭＲのロ
ック信号による磁場ドリフトと電圧の関係図である。
１・・・ＲＦ増幅器、２・・・検波器、３・・・直流ア
ンプ。
４・・・磁場制御アンプ、５・・・フィードバックコイ
ル。
６・・・スイッチ、７・・・リミッタ回路、８・・・制
御アンプ、９・・・スイッチ、１ｏ・・・磁石温度セン
サ、１１・・・差動型加算器、１２・・・温度制御アン
プ、１３・・・磁石ヒータ。FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between magnetic field drift and voltage due to an NMR lock signal. 1...RF amplifier, 2...detector, 3...DC amplifier. 4... Magnetic field control amplifier, 5... Feedback coil. 6... Switch, 7... Limiter circuit, 8... Control amplifier, 9... Switch, 1o... Magnet temperature sensor, 11... Differential type adder, 12... Temperature control Amplifier, 13...Magnetic heater.
Claims (1)
た検出器により連続した高周波や、パルスにより変調さ
れた高周波の局所磁場で励起した被測定試料の共鳴信号
を、受信、増幅、検波、さらにパルスで変調された時間
領域の信号は、フーリエ変換の手段を用いて周波数領域
に変換し、レコーダやＣＲＴに表示する分光器と、被測
定試料の溶媒に含まれる＾２Ｄ核の共鳴信号を受信、増
幅、検波し、制御回路で磁場制御信号として、磁石のポ
ール間に設置されたフィードバックコイルに供給して磁
場の安定性を保ち、一方永久磁石は電磁石と違つて磁石
自体で発熱することはないが、磁石材は温度勾配が強く
室温状態で使用するには、磁場値の変動が大きいため必
ず恒温槽に設置して、高精度の比例温度制御により磁石
温度を一定に保つようにしている温度制御から成る核磁
気共鳴装置において、該磁場制御用の信号の一部をリミ
ッター回路と制御アンプを通して磁石温度制御回路へ供
給し、磁石温度によるドリフトの一部を核磁気共鳴信号
から検出することを特徴とした核磁気共鳴装置の磁石温
度制御装置。1. A permanent magnet that generates a strong DC magnetic field and a detector installed on the magnet receive, amplify, and detect the resonant signal of the sample to be measured excited by a continuous high-frequency or pulse-modulated high-frequency local magnetic field. Furthermore, the pulse-modulated time domain signal is converted into the frequency domain using Fourier transform and displayed on a recorder or CRT using a spectrometer and the resonance signal of the ^2D nucleus contained in the solvent of the sample to be measured. The magnetic field is received, amplified, and detected by the control circuit and supplied as a magnetic field control signal to the feedback coil installed between the poles of the magnet to maintain the stability of the magnetic field.On the other hand, unlike electromagnets, permanent magnets generate heat within the magnet itself. However, since magnet materials have a strong temperature gradient and are used at room temperature, the magnetic field value will fluctuate greatly, so be sure to install it in a constant temperature bath and use highly accurate proportional temperature control to keep the magnet temperature constant. In a nuclear magnetic resonance apparatus consisting of temperature control, a part of the signal for controlling the magnetic field is supplied to the magnet temperature control circuit through a limiter circuit and a control amplifier, and a part of the drift due to the magnet temperature is detected from the nuclear magnetic resonance signal. A magnet temperature control device for a nuclear magnetic resonance apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62093059A JPS63259448A (en) | 1987-04-17 | 1987-04-17 | Magnet temperature controller for magnetic nuclear resonator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62093059A JPS63259448A (en) | 1987-04-17 | 1987-04-17 | Magnet temperature controller for magnetic nuclear resonator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63259448A true JPS63259448A (en) | 1988-10-26 |
Family
ID=14071939
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62093059A Pending JPS63259448A (en) | 1987-04-17 | 1987-04-17 | Magnet temperature controller for magnetic nuclear resonator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63259448A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002238873A (en) * | 2001-02-14 | 2002-08-27 | Ge Medical Systems Global Technology Co Llc | Magnetic field stabilizer, magnetic resonance imaging apparatus, and method of stabilizing magnetic field |
| WO2004010160A1 (en) * | 2002-07-22 | 2004-01-29 | Foxboro Nmr Ltd. | Frequency feedback for nmr magnet temperature control |
-
1987
- 1987-04-17 JP JP62093059A patent/JPS63259448A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002238873A (en) * | 2001-02-14 | 2002-08-27 | Ge Medical Systems Global Technology Co Llc | Magnetic field stabilizer, magnetic resonance imaging apparatus, and method of stabilizing magnetic field |
| JP4592975B2 (en) * | 2001-02-14 | 2010-12-08 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Magnetic field stabilization device, magnetic resonance imaging apparatus, and magnetic field stabilization method |
| WO2004010160A1 (en) * | 2002-07-22 | 2004-01-29 | Foxboro Nmr Ltd. | Frequency feedback for nmr magnet temperature control |
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