Evaluation Study of Tenant Office Building with Natural Ventilation and Personal Air-Conditioning System combined with Ceiling Radiation (Part 6) Measurement of Vertical Temperature Distribution inside NV Void under Actural Operation / 自然換気・放射併用パーソナル空調を導入したテナントオフィスビルの評価研究 (第6報)実運用下における自然換気用ボイド内の鉛直温度分布測定