long distance measurement with LVDT module

[uÖzkan]

Hi.

I need to measure the wall crack with LVDT but the measurment distance too long. That is aproximitly 70 m. 

If i use SCXI-1540 due to  voltage drop what it will happen.

[TobyHex]

Ultimately you will see signal degradation and possibly noise. Is there anyway for you to get the scxi module closer to the lvdt?

[uÖzkan]

So how long can the maximum SCXI to DAQ card cable  use to connect these device each other.

In this case i m using two SCXI chassis, some input module and PCI/ USB- 6281 daq card.

I found one cable for connecting that is SCXI-1353 Shielded Cable, 10 m 

but this distance so short for me maybe there is longer cable from that as customize

[TobyHex]

Hey Teknosat,

Take a look at the KnowledgeBase below for more information on this.

What is the Maximum Cable Length Between SCXI Chassis and PC?

Thanks again,

Nick

[Henrik_Volkers]

How about using a signal conditioner near the sensor that output a nicely scaled current loop?  

If you are stuck with that equipment: A lot of (digital ) filtering and a recalibration of the setup (appropriate fixure and two gauge blocks) . However with 70m (hopefully known type of) cable at not stable temperature I would also estinate the voltage drop of your exitation over temperatur ..