An issue that can be encountered with seismic work is when older geophones that are in your kit are no longer available.
It is advised to not mix and match phones especially when doing reflection. It is the customer’s responsibility to determine if using the newer 4.5 Hz geophones with older 4.5 Hz geophones will work for their situation, site requirements, etc.
When purchasing new geophones from Geometrics, check the response curve for the old geophones you have vs the new ones we sell.
Model Information:
- 4.5 Hz Response Curve_13-105-030D is for the old phones with the discontinued element.
- GS-ONE LF 2450 specs_Vert_147-00198_[13-105-090D] is the current phones we sell.
- RTC-4.5hz-395-Spec-Curve_147-00155 [13-205-004.5D]
Mixing geophones is not best practice, but they can be mixed so long as you understand the effect on the data when doing so. For surface wave and refraction surveys, it is OKAY, and not a big deal. When performing seismic reflection, mixing same frequency geophones with different response curves is not recommended. Even if not doing reflection, if the results of the data will potentially be used in court of law, or research uniformity is required, then all the geophones will need to be the same. Do your own research as ultimately the decision to either mix or not mix same frequency geophones with different response curves is up to you.
Here are the 4.5 Hz geophone datasheets with response curve information: