Contents
p. 2Applic.
pp. 4-8

Selection
pp. 9-11

Products
pp. 12-87

GenRadproducts
pp. 50-87

高度キャパシタンス
Precision
Capacitance
測定システムMeasurement SystemIndex
p. 891238 Detector
Designedfor the difficult. If you‛ve ever had to
困難に挑戦した設計
ノイズの中から小さい信号を抽出しextracta small signal from noise or to resolve a signal
たり、信号を同相成分と直交成分に分解した事のある方
into
its in-phase and quadrature components, you can
であれば1238の利点の真価を分かって頂けるはずです。
appreciate
the advantages of the 1238. With its high130dBの高ゲインとメータは単に入力信号の強度のため
gain -130 dB-and meters not only for magnitude of theにだけではなく、同相成分と直交成分の分解にも役立
input signal but for the in-phase and quadrature compoち、非常に難しい応用でも1238を使用すれば容易にでき
nents as well, the 1238 lends itself handily to the mostます。 applications.
exacting
この高機能の検知器はその他の点でも特長があります。最This
high-performance detector is attractive in other
小負荷の為の1GΩ入力インピーダンス、200Vまでの信号
respects
also, including 1-GΩ input impedance forminimumloading,
overload protection against signals up
に対する過負荷保護、信号にいかにノイズが含まれていて
to200 V. and flat or tuned frequency response (with orも検知器を調整するフラットあるいは同調周波数応答（電withoutline-frequency rejection) to tailor the detector
源周波数除去有り、あるいは無しで）などの機能です。
to your signal no matter how “tainted” it might be.
優れたブリッジ検知器
必要な直交基準チャンネルを供給
Excellent
bridge detector.
In combination with a
する特別な発振器、GR1316と組み合わせることで、このspecial oscillator, GR 1316, that supplies the neces検知器は優れた音声周波検知器になります。1238検知器
sary
quadrature reference channels, this detector issuperb
for sensitive audio-frequency detectlbn. Theは特に1616精密キャパシタンスブリッジと組み合わせてcombinationis specifically intended for use withthe-6の分解能使用する事を意図して作られており、10pFの101616Precision
CapacitanceBridge,enablingresolutionsを可能にしています。1621精密キャパシタンス測定シス
of one part in 106 of 10 pF. Refer to the 1621 Precision
テムの項も参照して下さい。
CapacitanceMeasurement System.
1238検知器はハイインピーダンスのローノイズプリアン
The 1238 Detector consists of a high-impedance lownoise preamplifier, a tuned amplifier, a compression
プ、同調アンプ、圧縮アンプと二つの位相敏感検知器で構成
amplifier, and two phase-sensitive detectors. Three
されています。三つのパネルメータはそれぞれ入力信号の強panel meters provide the indications: one displays the度、同相成分、直交成分を同時に示します。基準信号を0°
magnitude of the input signal and two others simultaneから360°連続的に回転させる事ができるので、最も高感度
ously display its in-phase andなブリッジバランスあるいは信号解析でも位相メータはquadrature components. The reference signals can beそれぞれ独立して応答します。
rotated continuously from 0 through 360° to ensurethat the phase meters respond independently to the
ハムや入力信号のその他の汚染によるノイズの影響は、
components of significance to you, for the most rapid
フロントパネルのプッシュボタンを単に押すかツマミを
bridge balances or signal analysis.
回すことでコントロールできる同調フィルタ、ラインノイズ除去フィルタ、位相敏感検知回路の時定数選択によThe effects of noise, hum, or any other input-signal
り、通常は測定システムから除去あるいは削減できま
contaminants are normally reduced or eliminated fromす。
your measurements by means of a tunable filter, linerejection filter, and selectable time constants in thephase-sensitive detector circuits - all controlled fromthe front panel by the simple push of a button or turnof a knob.

～ 100 kHz
10 Hz to素早くブリッジバランスを取る為の、強度、同相、
magnitude,
in-phase, and quadrature meters for

全領域での感度100-nS full-scalesensitivity

rapid bridge balances

直交の三つのメータ

優れたブリッジ検出器
excellent
bridge detector

SPECIFICATIONS
仕 様
周波数: 10 Hz to 100 kHz, flat or tuned. FLAT: ±5 dB from 10Frequency:
Hz to 100 kHz. TUNED: Set by 4 in-line readout dials with ±5%of reading accuracy, 2 to 4% bandwidth, and second harmonic
30 dB down from peak. LINE-REJECTION FILTER: Reduces line
level by 40 dB while signal is down 6 to 10 dB at 10 Hz from line
frequency; filter can be switched out.
ブリッジあるいは他ソースからの入力信号:
Signal Input from bridge or other source: Applied to rear BNC-connector. SENSITIVITY: Also see curve; 100 nS rms typical for
full-scale deflection at most frequencies, compression can beswitched in to reduce full-scale sensitivity by 20 dB. IMPEDANCE:1 GΩ//20 pF. MAXIMUM INPUT: 200 V rms. VOLTAGE GAIN: ~105
dB in flat mode, ~130 dB in tuned mode. set by 12-position switch.
−SPOT NOISE VOLTAGE: <30 nS x √ bf andwidthHz at 1 kHz withinput impedance of 70 MΩ//500 pF. MONITORED by magnitude,in-phase, and quadrature meters; phase-sensitive detectors contain time-constant vairable from 0.1 to 10 s in 5 steps.

on Magnitude meter) available at rear BNC connector. MAGNITUDE: 6 V dc for full scale deflection; PHASE DETECTORS: Upto 1 V dc each for full scale deflection (depending on Sensitivitysetting); available at rear 5-pin type 126 jack.
環境:
Environment:
TEMPERATURE: 0 to +55°C operating, -40 to+75°C storage. BENCH HANDLING: 4 in. or 45° (MIL-810A-VI).
SHOCK: 30 G, 11 ms (MIL-T-4807A-4.5-3A).
必需品: Oscillator with 0 and 90° outputs; the 1316 Oscillator isRequired:recommended.

Power: 100 to 125 and 200 to 250 V. 50 to 60 Hz. 15 W.
パワー:
Mechanical:
Bench or rack models.
形状:
卓上型あるいはラックマウント型
大きさ:
DIMENSIONS:
Bench: 16.9 cm H x 49.7 cm W x 32.9 cm D (6.66"x19.56"x12.94")
Rack, 13.3 cm H x 48.3 cm W x 33.2 cm D (5.22"x19"x13.06").

オシレータからの基準入力:
Reference Inputs from oscillator: Applied to rear BNC connec-

WEIGHT: Bench: 13 kg (27 Ib) net, 19 kg (40 lb) shipping, rack 10
重さ:

tors. Two 1-V rms reference signals required, with 90° phasedifference between them. PHASE SHIFTER rotates both references continuously from 0 to 360° and two verniers rotate eachreference individually ~10°.

kg (21 lb) net, 16 kg (34 lb) shipping.

Outputs:
MAIN AMPLIFIER: 4 V rms (approx 2.3 V for full scale
出力: メインアンプ:

ORDERING:
1238-9700
60-Hz Bench Model
品番:1238-9701 60-Hz Rack Model
1238-9703 50-Hz Bench Model
1238-9704 50-Hz Rack Model

IET LABS, INC. in the GenRad Tradition
534 Main Street, Westbury, NY 11590
86

www.ietlabs.com
TEL: (516) 334-5959 • (800) 899-8438 • FAX: (516) 334-5988