概览
255-100 根据蒸发皿中的水位变化来测定蒸发率。蒸发计产生输出电阻可以被数据采集器检测到。255-200或其它标准的国家气象服务A级蒸发皿需单独采购。
优势与特点
- Compatible with most Campbell Scientific data loggers
- Low-power device for reading the water level of an evaporation pan such as the 255-200
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技术说明
255-100 包括一个浮标、滑轮和平衡装置，它们装在一个精密的1000-ohm的电位计上，通过齿轮装置安装在防水外箱里面。配有带三个水平螺母和一个水平仪的三角板。电位计产生的输出阻抗与浮标的方位成比例，现场利用数据采集器，或远程使用监测设备可检测到传感器的信号。
255-100 可直接放在蒸发皿中，或是使用255-100P/F与蒸发皿连接。 如不使用255-100P/ F，可使用1/2-英寸的polybraid（纤维加固）软管，尼龙接头（1/2-英寸，NPT X Hose Bar）和小型不锈钢喉箍，这些配件可从当地的五金商店购买。
产品规格
| Water Input Port | 1/2-in. NPT coupling, female |
| Counter Weight | 114 g (4 oz) stainless steel |
| Total Resolution | 0.76 mm (0.03 in.) |
| Potentiometer Accuracy | 0.25% |
| Rotation | 360° continuous |
| Electrical Angle | 340°, ±1° (20° gap) |
| Resistance | 1,000 ohm, ±10% |
| Operating Temperature Range |
-40° to +60°C Evaporation is normally not measured at temperatures below freezing. |
| Linearity | 0.25% |
| Mechanical Range | 0 to 254 mm (0 to 10 in.) |
| Electrical Range | 0 to 240 mm (0 to 9.44 in.) |
| Float | 10.2 cm (4 in.) diameter, plastic |
| Cable Description | 3-conductor, 24 AWG, shielded |
| Cable Length | 15 m (50 ft) |
| Diameter | 203 mm (8 in.) |
| Height | 700 mm (27.5 in.) |
| Base Dimensions | 40.6 cm (16 in.) triangle with leveling screws |
| Weight | 3.4 kg (7.5 lb) |
| Shipping Weight | 6.8 kg (15 lb) |
常见问题解答
255-100: 2
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The 255-100 Evaporation Gauge is a potentiometer-type sensor. The 255-100 only draws a few milliamps of power momentarily. If the 255-100 is the only sensor in the system, the data logger has an average power draw of approximately 1 mA.
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The Half Bridge instruction should be selected (not the 3 Wire or 4 Wire options) in Short Cut. The following parameters are data logger specific, but the following can be used on the CR1000 datalogger with the sensor wired to SE1, and Vx1:
How many HalfBr Sensors? 1 Total Bridge Resistance 1000 ohm Excitation Voltage 2500 mV Sensors per excitation channel 1 Range of sensor voltage 2500 mV Reverse Excitation Yes Measurement Integration 50 or 60Hz
Settling Time 20000 µs Multiplier Determined during installation (see manual) Offset Determined during installation (see manual)