[SAC-HELP] How to remove the instrument response?

[Mohamed Kamaleldin Abdel Galeil Salah]

Hi all,

I have some BB SAC files for a sensor CMG-40TD (Guralp systems) and I  
want to remove the instrument response from the seismogram.
I prepared a file ´pz´'as follows:
ZEROS  4
0    0
0   159

POLES  3
-50.0   0.0
-0.02356 + j0.02356
-0.02356 - j0.02356

CONSTANT  -0.314

I have two questions:

1. Is such data ok for the instrument type given above?
2. when I run the command: transfer from polezero subtype pz to none,   
from within SAC, I get the following message:

  Extracting polezero response for MTE     , BHZ...

Station (MTE     ), Channel (BHZ)
	Calper is not available. Cannot tell if response is normalized, so  
transfer function will be used without scaling.
	Calib is not available. Cannot tell if scale factor has been applied  
on input, so transfer function will be used without scaling.
	Waveform multiplied by 1.000000 after deconvolution.

How I can fix this error?

Thanks