in src/outmdsd/DjsonLogItem.h [100:106]
void AddData(std::string name, double value)
{
// because std::to_string(double) only prints 6 deciman digits, don't use it
std::ostringstream strm;
strm << value;
m_svlist.emplace_back(std::move(name), "FT_DOUBLE", strm.str());
}