The Columbia SA-220RHT and SA-225RHT Force Balance Accelerometers are designed to be used as Measurement While Drilling (MWD) sensors in downhole well servicing applications. The Model SA-220RHT is powered by ±15 VDC and can withstand temperatures of up to 200 °C.
The model SA-225RHT runs at 190 °C and requires ±5 VDC. Both sensors are self-contained and give a high-level, low-impedance output, avoiding the need for signal conditioning at high temperatures.
The SA-220RHT and SA-225RHT sensors have become the established standard used in downhole high-temperature mapping because of their remarkable high-temperature performance, tough design and low power consumption.
- Choice of power options
- 200 °C and 190 °C operation
- Biaxial sensors
Image Credit: Columbia Research Laboratories, Inc.
Specifications
Operational
Table 1. Source: Columbia Research Laboratories, Inc.
| Operational |
SA-220RHT |
SA-225RHT |
| Ranges Available |
±1 G to ±10 G |
±1 G to ±5 G |
| Output Voltage |
±5 Volts ±2%
Into 100 K Load |
±3 Volts ±2%
Into 100 K Load |
| Excitation |
±15 VDC
<40 mA |
±5 VDC
<20 mA |
| Case Alignment |
<0.5° |
| Non-Linearity |
±0.05% F.R. |
±0.10% F.R. |
| Hysteresis |
±0.07% F.R. |
±0.15% F.R. |
| Non-Repeatability |
±0.10% F.R. |
±0.15%FR. |
| Resolution |
<0.001% F.R. |
<0.002% F.R. |
| Zero Bias |
±0.15% F.R. |
±0.25% F.R. |
| Zero Bias Temp. Coefficient |
±0.002% F.R./°C |
±0.003% FR/°C |
| Scale Factor Temp. Coefficient |
±0.025%/°C |
| Natural Frequency |
50 Hz to 300 Hz
Dependent on Range |
50 Hz to 250 Hz
Dependent on Range |
| Damping Ratio |
0.6 to 1.0 |
0.7±0.2 |
| Cross Axis Sensitivity |
0.01 G/G |
Environmental
Table 2. Source: Columbia Research Laboratories, Inc.
| Environmental |
SA-220RHT |
SA-225RHT |
| Temperature, Operating |
-40 to +200 °C |
-40 to +190 °C |
| Temperature, Storage |
-50 to +200 °C |
| Random Vibration (2 to 2000 Hz) |
25 G RMS, 0.5'' Disp. D.A |
| Shock Survival |
500 G, 0.5 mS |
Physical
Table 3. Source: Columbia Research Laboratories, Inc.
| Physical |
SA-220RHT |
SA-225RHT |
| Weight |
3.34 oz (94.7 gm) |
| Size |
1.13"Sq. x 2.285"H (2.9 cm Sq x 5.8"H) |
| Case Material |
Nickel Plated Aluminum |
| Sealing |
Environmental |
| Electrical Interface (Standard) |
6 Terminal Pins |
Vertical Mounting Plate Columbia P/N AFB04418P01. Image Credit: Columbia Research Laboratories, Inc.
Horizontal Mounting Plate Columbia P/N AFB04418P02. Image Credit: Columbia Research Laboratories, Inc.
I/O Connector Pin Functions
Table 4. Source: Columbia Research Laboratories, Inc.
| SA-220RHT |
| Pin |
Function |
| 1 |
+15 VDC |
| 2 |
Ground |
| 3 |
-15 VDC |
| 4 |
X Output |
| 5 |
Ground |
| 6 |
Y Output |
| Pins 2 & 5 are common ground to pwr supply and both outputs |
Table 5. Source: Columbia Research Laboratories, Inc.
| SA-225RHT |
| Pin |
Function |
| 1 |
+5 VDC |
| 2 |
Ground |
| 3 |
-5 VDC |
| 4 |
X Output |
| 5 |
Ground |
| 6 |
Y Output |
| Pins 2 & 5 are common ground to pwr supply and both outputs |