Application Introduction

Why measure oxygen partial pressure?

Oxygen partial pressure can calculate the water vapor content, that is, the oven is working properly and calculate the current relative humidity in the cabinet.

Relative humidityRH%= (WVP÷WVPmax) x 100% =｛[BP-(ppO2÷0.2095)]÷WVPmax｝x 100%

Among them:

WVPmax is the saturated water vapor pressure at the current temperature, and the temperature value in the steamer needs to be known.

WVP real-time water vapor pressure.

PPO2 oxygen partial pressure in the box.

BP is the value of the air pressure inside the steaming oven.

Why measure relative humidity?

Bread crust color：

High humidity will make the crust of baked goods lighter in color. This is because excessive humidity prevents the direct transfer of heat to the product. In addition, the condensate formed on the surface of the dough acts as a natural insulation for heat transfer. In this case, the temperature of the crust during baking is lower than the target temperature, resulting in a light-colored finished product.

Dough expansion and product volume：

High humidity increases the volume of baked products. A moisture-rich baking chamber reduces the driving force for moisture migration. Therefore, the product loses less moisture in the hot air, making the dough/The batter remains moist and expands further before the dough sets/Stretch.

Moisture content：

High humidity will increase the moisture content of baked products, which will affect the shelf life and slicing of the products.

Bread crust characteristics：

Some artisanal and hearth breads require steaming to produce surface condensation and produce a shiny crust. The higher the humidity, the smoother and thicker the product shell.

How to adjust the relative humidity?

Purging system:

Oven humidity and heat distribution is usually determined by a fixed-speed suction fan and/or damper control. They can be adjusted manually orPLCThe controlled electric valve is adjusted. In modern steam ovens, it is usually controlled by a variable speed suction fan.

Fresh air:

In some applications, for safety reasons, the hot and humid air can be replaced by fresh air during the baking cycle, thereby improving product characteristics.

Steam Injection:

Monitor and adjust the saturation level, pressure and amount of steam injected into the oven, baking oven and handmade bread.

The following figure shows the difference in humidity in the steaming oven when the damper is open or closed:

Damper open:

Here,To recommend you a detection of oxygen sensorO2S-FR-T4。

This sensor is British.SSTA small gas sensor specially developed for detecting oxygen partial pressure.

Input:

Work:4.35VDC±0.1VDC (1.85A)

Standby:2VDC (0.85A)

Output (used with one of the following boards):

O2I-Flex: digital signalRS232, analog signal4~20mA，0~10Vd. Support3The signals are output at the same time.

OXY-LC: Digital signal:RS485, analog signal:4~20mAor0~10Vdc. Only3Select1signal output.

Wiring:

Parameters:

Order: