# Double-C Seismic Accelerometer

 Double-C Seismic Accelerometer Environmental sensor Radial size Radial mounted Cost (total) 6 000.00 Mass (total) 0.00500 t [N 1] Drag 0.2 [N 1] Max. Temp. 1200 K Volume ? Impact Tolerance 8 m/s Research Electronics Unlock cost 8 200 Since version 0.18 Part configuration sensorAccelerometer.cfg Experiment Seismic Scan Electricity required 0.0075 ⚡/s The mass and drag are from the part config, but the game handles it as physicsless.

The Double-C Seismic Accelerometer is a scientific instrument and environmental sensor that measures a craft's acceleration. It displays the g-force on the craft.

In career mode, it is available with Electronics, at level 7 of the technology tree.

## Product description

 “ This device contains an extremely sensitive acceleration sensor, which when properly settled on a firm surface, will detect and record accurate seismic activity data. The accelerometer will still function while flying, so the Double-C can also be used to measure accelerations during flight. Warranty void if shaken or exposed to vacuum.— Probodobodyne Inc ”

## Usage

The Double-C Seismic Accelerometer can be radially mounted to a vessel. It is a physicsless part, and its mass and drag are instead added to its parent part.

### Science experiment

→ Main article: Science#Modules
 Experiment Seismic Scan Double-C Seismic Accelerometer 50 Mits 20 22 2.5 45% 500 ⚡

Right-clicking on the Double-C Seismic Accelerometer (from the vessel or from a scientist on EVA) will reveal an option to "Log Seismic Data". Using this option will make the Double-C perform a Seismic Scan, which can earn the player Science.

Unlike other experiments, a Seismic Scan can only be performed while landed on a celestial body; the vessel must be resting on land. If in any other situation (splashed in the ocean, flying in the atmosphere, in space, etc.), then the experiment cannot be performed. However, once landed, a unique Seismic Scan can be done in each biome.

To perform a Seismic Scan from water biomes (e.g. Kerbin's Oceans), a craft with the Double-C can be sunk into the water, coming to rest on the ocean floor.

Like other scientific instruments, the Double-C Seismic Accelerometer can only hold one experiment at a time. Attempting to perform a Seismic Scan while the Double-C already contains one will result in the original scan being overwritten. To avoid this, the scan should be transferred out of the Double-C Seismic Accelerometer. This can be done by a Kerbal on EVA, or by an Experiment Storage Unit (or probe core with built-in storage functionality).

Once the Seismic Scan has been removed from the Double-C Seismic Accelerometer, it can be reused to perform another Seismic Scan.

### Environmental sensor

Attached to the side of an ascent stage this environmental sensor can be used to control your acceleration during launch to provide a better and constant ascent, using less fuel for the same orbit. The Double-C displays 4 significant figures, offering much better precision than the g-meter on the navball. On upper and cruise stages the Double-C Accelerometer can be used to estimate the time needed to accelerate to a certain speed.

Additionally it can be used to measure the spacecraft's current mass indirectly using Newton's second law. To estimate the mass, activate the accelerometer and fire the engines so that the craft isn't rotating.

${\displaystyle m={\frac {F}{a}}}$ Given the force F by adding all engines forces together and the acceleration a by the accelerometer the current mass is the division of both. But as the craft is losing mass by this the acceleration is increasing over time. Thus it's only accurate at a low fuel burn rate over a short period of time. This will also change the craft's orbit, so maybe a retroburn afterwards is necessary.

Since version 0.20 this method serves little purpose, because the exact mass of a vehicle can be seen in the map view and tracking station.

While active, the accelerometer drains 0.0075 Electric Charge per second (27 E/h).

## Trivia

• Apart from the two scenarios in the product description, there exists another easter egg situation that can void the Double-C Seismic Accelerometer's warranty.
Spoiler: Easter egg voiding warranty
• If landed on the surface of the gas giant Jool (a normally impossible feat), performing a Seismic Scan may yield the message:
 “ The sensor has informed you that the warranty has just been voided. No refunds. ”
→ Main article: Jool#Trivia

## Changes

0.23.5
• "PhysicsSignificance = 1" added. The part now has 0 mass and drag, despite the listed values.
0.22
• Renamed from Double-C Accelerometer to Double-C Seismic Accelerometer