POCKET PEN DISSOLVED OXYGEN METER DOMeasurement range (0 ~ 20) mg/L Temperature range (0 ~ 40) ℃ DO Basic error + / - 0.3mg/L Temperature Basic error + 1 ℃ Residual current ＜0.15mg/L Response time ＜30s (20 ℃ when the 90% response) Automatic temperature compensation range 0 ~ 40 ℃ Power 1.5V button battery (4pcs) Size and weight 40mm*185mm & 88g