The MicroTesla NDS, New Digitized Sensor, is a completely new “drop-in” replacement sensor for QDT products.
It has a one-piece chassis made from a solid billet of 6061-T6 aluminum and it uses NO end adapters. The ends are machined to fit the Customers snubber (shock isolator) and MWD controller chassis ends. No end adapters mean no “loose” end adapters and no end adapter misalignment.
The NDS has (1) electronic board for all functions including core drive, mag sense, analog to digital conversion and power control. The NDS uses (3) Q-flex accelerometers and (2) two-axis MicroTesla magnetometers. The ultra-strong, stiff chassis means that the accelerometer and magnetometer misalignments are eliminated.
The NDS is a 175 deg C instrument which uses the many new high temperatures (210 deg C +) electronic components.
Physical
Length: Min 24”, Max 29.3” Nominal
Diameter: 1.37”
(2) MicroTesla proprietary two-axis fluxgate magnetometers
(3) Q-flex accelerometers
Compatible with all QDT, MWD/Em Systems
Electrical
Surface mount high temp electronics with Sylgard Encapsulation
Voltage requirement: +/-12V to +/-15V
Power Usage: .7W peak, 0.3W idle
Digital interface: SPI
Calibration coefficients downloaded directly into the sensor’s digital
interface serial memory or the MWD Controller
Environmental
All boards qualified for high-temp applications, 175C
QFlex accelerometers qualified, 185C
MicroTesla magnetometers qualified, 210C
Stronger stiffer chassis for improved resistance to bend and torsion twist
Mechanical and Environmental Specifications
| Parameter | Minimum | Maximum | Units |
|---|---|---|---|
| Outside Diameter* | 1.37 3.5 |
inches cm |
|
| Length* | 29.3 74.4 |
inches cm |
|
| Operating Temperature | 0 + 32 |
175 347 |
°C °F |
| Survival Temperature | – 40 – 40 |
190 374 |
°C °F |
| Vibration, Random | 25 | g RMS, 25-500 Hz | |
| Shock | 1000 | ½ msec and ½ sine |
Instrument Accuracy Specifications
| Parameter | Minimum | Units |
|---|---|---|
| Inclination accuracy, absolute* | ± 0.08 | degrees |
| Inclination spread on axial rotation at 90° Inc | < 0.08 | degrees |
| Azimuth accuracy, absolute, 90° Inc | ± 0.4 | degrees |
| Azimuth spread axial rotation, 45° through 90° | < 0.35 | degrees |
| Total face accuracy, axial rotation at 90° Inc | ± 0.7 | degrees |
| Total g field accuracy | ± 2.5 | mG |
| Total H field accuracy, absolute | ± 180 | nT |
| Total H field spread | < 150 | nT |
| Magnetic dip accuracy | ± 0.2 | degrees |
| Dip angle spread | < .25 | degrees |